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The ______ register is read by the host to get input. a) flow in b) flow out c) data in d) data out

The ________ keeps state information about the use of I/O components. a) CPU b) OS c) kernel d) shell

Swapping requires a __________. a) motherboard b) keyboard c) monitor d) backing store

Caching is ________ spooling. a) same as b) not the same as c) None of these

A floppy disk is designed to rotate ___________ as compared to a hard disk drive. a) faster b) slower c) at the same speed d) None of these

Operating System maintains the page table for a) each process b) each thread c) each instruction d) each address

Program always deals with a) logical address b) absolute address c) physical address d) relative address

RAID level _______ refers to disk mirroring. a) 0 b) 1 c) 2 d) 3

Illegal addresses are trapped using the _____ bit. a) error b) protection c) valid - invalid d) access

A dedicated device is : (choose all that apply) a) opposite to a sharable device b) same as a sharable device c) can be used concurrently by several processes d) cannot be used concurrently by several processes

A single parity bit can be used for : (choose all that apply) a) detection b) multiple error corrections c) few error corrections d) single error correction

The two atomic operations permissible on semaphores are : (choose two) a) wait b) stop c) hold d) signal

What is compaction? a) a technique for overcoming internal fragmentation b) a paging technique c) a technique for overcoming external fragmentation d) a technique for overcoming fatal error

What is the mounting of file system? a) crating of a filesystem b) deleting a filesystem c) attaching portion of the file system into a directory structure d) removing portion of the file system into a directory structure

A deadlock avoidance algorithm dynamically examines the __________, to ensure that a circular wait condition can never exist. a) resource allocation state b) system storage state c) operating system d) resources

A locality is : a) a set of pages that are actively used together b) a space in memory c) an area near a set of processes d) None of these

A process having multiple threads of control implies : a) it can do more than one task at a time b) it can do only one task at a time, but much faster c) it has to use only one thread per process d) None of these

A process is thrashing if a) it is spending more time paging than executing b) it is spending less time paging than executing c) page fault occurs d) swapping can not take place

A semaphore is a shared integer variable a) that can not drop below zero b) that can not be more than zero c) that can not drop below one d) that can not be more than one

A single swap space ______ reside in two places. a) can b) cannot c) must not d) None of these

A solution to the problem of external fragmentation is : a) compaction b) larger memory space c) smaller memory space d) None of these

A system has 3 processes sharing 4 resources. If each process needs a maximum of 2 units then, deadlock : a) can never occur b) may occur c) has to occur d) None of these

Linux __________ the use of multiple swap spaces. a) allows b) does not allow c) None of these

Mapping of file is managed by a) file metadata b) page table c) virtual memory d) file system

Mapping of network file system protocol to local file system is done by a) network file system b) local file system c) volume manager d) remote mirror

The address loaded into the memory address register of the memory is referred to as : a) physical address b) logical address c) Neither a nor b

The size of a process is limited to the size of : a) physical memory b) external storage c) secondary storage d) None of these

The solution to starvation is : a) the number of rollbacks must be included in the cost factor b) the number of resources must be included in resource preemption c) resource preemption be done instead d) All of these

What is the reusable resource? a) that can be used by one process at a time and is not depleted by that use b) that can be used by more than one process at a time c) that can be shared between various threads d) none of the mentioned

Which facility dynamically adds probes to a running system, both in user processes and in the kernel? a) DTrace b) DLocate c) DMap d) DAdd

Windows NT uses a __________ implementation for I/O a) message - passing b) draft - passing c) secondary memory d) cache

With multiprogramming, ______ is used productively. a) time b) space c) money d) All of these

______ is a unique tag, usually a number, identifies the file within the file system. a) File identifier b) File name c) File type d) none of the mentioned

_________ replacement allows each process to only select from its own set of allocated frames. a) Local b) Universal c) Global d) Public

__________ is generally faster than _________ and _________. a) first fit, best fit, worst fit b) best fit, first fit, worst fit c) worst fit, best fit, first fit d) None of these

The most optimal scheduling algorithm is : a) FCFS - First come First served b) SJF - Shortest Job First c) RR - Round Robin d) None of these

The offset 'd' of the logical address must be : a) greater than segment limit b) between 0 and segment limit c) between 0 and the segment number d) greater than the segment number

The segment of code in which the process may change common variables, update tables, write into files is known as : a) program b) critical section c) non - critical section d) synchronizing

The signal operation of the semaphore basically works on the basic _______ system call. a) continue() b) wakeup() c) getup() d) start()

The header and trailer of a sector contain information used by the disk controller such as _________ and _________. a) main section b) error correcting codes (ECC) c) sector number d) disk identifier

When a fixed amount of swap space is created during disk partitioning, more swap space can be added only by : I) repartitioning of the disk II) adding another swap space elsewhere a) only I b) only II c) both I and II d) neither I nor II

When a page fault occurs, the state of the interrupted process is : a) disrupted b) invalid c) saved d) None of these

When a program tries to access a page that is mapped in address space but not loaded in physical memory, then a) segmentation fault occurs b) fatal error occurs c) page fault occurs d) no error occurs

When the entries in the segment tables of two different processes point to the same physical location : a) the segments are invalid b) the processes get blocked c) segments are shared d) All of these

Binding of instructions and data to memory addresses can be done at : a) Compile time b) Load time c) Execution time d) All of these

Buffering is done to : a) cope with device speed mismatch b) cope with device transfer size mismatch c) maintain copy semantics d) All of these

In the Zero capacity queue : (choose two) a) the queue has zero capacity b) the sender blocks until the receiver receives the message c) the sender keeps sending and the messages dont wait in the queue d) the queue can store atleast one message

The child process can : (choose two) a) be a duplicate of the parent process b) never be a duplicate of the parent process c) have another program loaded into it d) never have another program loaded into it

Bounded capacity and Unbounded capacity queues are referred to as : a) Programmed buffering b) Automatic buffering c) User defined buffering d) No buffering

The OS X has a) monolithic kernel b) hybrid kernel c) microkernel d) monolithic kernel with modules

A process is selected from the ______ queue by the ________ scheduler, to be executed. a) blocked, short term b) wait, long term c) ready, short term d) ready, long term

Several processes access and manipulate the same data concurrently and the outcome of the execution depends on the particular order in which the access takes place, is called a(n) ____. a) Shared Memory Segments b) Entry Section c) Race condition d) Process Synchronization

The device-status table contains a) each I/O device type b) each I/O device address c) each I/O device state d) all of the mentioned

In UNIX, two per process ________ are used by the kernel to track swap space use. a) process tables b) swap maps c) memory maps d) partition maps

In internal fragmentation, memory is internal to a partition and : a) is being used b) is not being used c) is always used d) None of these

Multithreading on a multi - CPU machine : a) decreases concurrency b) increases concurrency c) doesnt affect the concurrency d) can increase or decrease the concurrency

A ________ is a collection of electronics that can operate a port, a bus, or a device. a) controller b) driver c) host d) bus

________ replacement generally results in greater system throughput. a) Local b) Global c) Universal d) Public

The ___________ swaps processes in and out of the memory. a) memory manager b) CPU c) CPU manager d) user

A mutex : a) is a binary mutex b) must be accessed from only one process c) can be accessed from multiple processes d) None of these

A performance problem with _________ is the expense of computing and writing parity. a) non-parity based RAID levels b) parity based RAID levels c) all RAID levels d) None of these

A problem encountered in multitasking when a process is perpetually denied necessary resources is called a) deadlock b) starvation c) inversion d) aging

A process is moved to wait queue when I/O request is made with a) non-blocking I/O b) blocking I/O c) asynchronous I/O d) synchronous I/O

If the resources are always preempted from the same process, __________ can occur. a) deadlock b) system crash c) aging d) starvation

If the sum of the working - set sizes increases, exceeding the total number of available frames : a) then the process crashes b) the memory overflows c) the system crashes d) the operating system selects a process to suspend

Smaller page tables are implemented as a set of _______. a) queues b) stacks c) counters d) registers

The data-in register of I/O port is a) read by host to get input b) read by controller to get input c) written by host to send output d) written by host to start a command

The dining - philosophers problem will occur in case of : a) 5 philosophers and 5 chopsticks b) 4 philosophers and 5 chopsticks c) 3 philosophers and 5 chopsticks d) 6 philosophers and 5 chopsticks

Which buffer holds the output for a device? a) spool b) output c) status d) magic

Which one of the following is a visual ( mathematical ) way to determine the deadlock occurrence? a) resource allocation graph b) starvation graph c) inversion graph d) none of the mentioned

Which one of the following is the deadlock avoidance algorithm? a) banker's algorithm b) round-robin algorithm c) elevator algorithm d) karn's algorithm

The data structures available in the Banker's algorithm are : (choose all that apply) a) Available b) Need c) Allocation d) Maximum e) Minimum f) All of these

ABCD

File type can be represented by a) file name b) file extension c) file identifier d) none of the mentioned

When the head damages the magnetic surface, it is known as _________. a) disk crash b) head crash c) magnetic damage d) All of these

What is the drawback of banker's algorithm? a) in advance processes rarely know that how much resource they will need b) the number of processes changes as time progresses c) resource once available can disappear d) all of the mentioned

All unsafe states are : a) deadlocks b) not deadlocks c) fatal d) None of these

If a process is executing in its critical section, then no other processes can be executing in their critical section. This condition is called a) mutual exclusion b) critical exclusion c) synchronous exclusion d) asynchronous exclusion

CPU scheduling is the basis of ____________. a) multiprocessor systems b) multiprogramming operating systems c) larger memory sized systems d) None of these

'm' processes share 'n' resources of the same type. The maximum need of each process doesn't exceed 'n' and the sum of all their maximum needs is always less than m+n. In this setup, deadlock : a) can never occur b) may occur c) has to occur d) None of these

A FIFO replacement algorithm associates with each page the _______ a) time it was brought into memory b) size of the page in memory c) page after and before it d) All of these

A computer system has 6 tape drives, with 'n' processes competing for them. Each process may need 3 tape drives. The maximum value of 'n' for which the system is guaranteed to be deadlock free is : a) 2 b) 3 c) 4 d) 1

A thread is also called : a) Light Weight Process(LWP) b) Heavy Weight Process(HWP) c) Process d) None of these

All processes share a semaphore variable mutex, initialized to 1. Each process must execute wait(mutex) before entering the critical section and signal(mutex) afterward. ii) Suppose a process executes in the following manner (replacing signal with wait) : a) a deadlock will occur b) processes will starve to enter critical section c) several processes maybe executing in their critical section d) All of these

An SJF algorithm is simply a priority algorithm where the priority is : a) the predicted next CPU burst b) the inverse of the predicted next CPU burst c) the current CPU burst d) anything the user wants

An asynchronous call : a) returns immediately, without waiting for the I/O to complete b) does not return immediately and waits for the I/O to complete c) consumes a lot of time d) is too slow

An edge from process Pi to Pj in a wait for graph indicates that : a) Pi is waiting for Pj to release a resource that Pi needs b) Pj is waiting for Pi to release a resource that Pj needs c) Pi is waiting for Pj to leave the system d) Pj is waiting for Pi to leave the system

An unrecoverable error is known as _________. a) hard error b) tough error c) soft error d) None of these

Another solution to the problem of external fragmentation problem is to : a) permit the logical address space of a process to be noncontiguous b) permit smaller processes to be allocated memory at last c) permit larger processes to be allocated memory at last d) All of these

Because of virtual memory, the memory can be shared among a) processes b) threads c) instructions d) none of the mentioned

Bounded waiting implies that there exists a bound on the number of times a process is allowed to enter its critical section : a) after a process has made a request to enter its critical section and before the request is granted b) when another process is in its critical section c) before a process has made a request to enter its critical section d) None of these

CPU fetches the instruction from memory according to the value of a) program counter b) status register c) instruction register d) program status word

Complex scheduling algorithms : a) are very appropriate for very large computers b) use minimal resources c) use many resources d) All of these

Consider the following page reference string : 1 2 3 4 2 1 5 6 2 1 2 3 7 6 3 2 1 2 3 6 i) For LRU page replacement algorithm with 4 frames, the number of page faults is : a) 10 b) 14 c) 8 d) 11

Consider the following page reference string : 1 2 3 4 2 1 5 6 2 1 2 3 7 6 3 2 1 2 3 6 iii) For FIFO page replacement algorithms with 3 frames, the number of page faults is : a) 16 b) 15 c) 14 d) 11

Consider the following set of processes, the length of the CPU burst time given in milliseconds : Process Burst time P1 6 P2 8 P3 7 P4 3 i) Assuming the above process being scheduled with the SJF scheduling algorithm : a) The waiting time for process P1 is 3ms. b) The waiting time for process P1 is 0ms. c) The waiting time for process P1 is 16ms. d) The waiting time for process P1 is 9ms.

Deadlock prevention is a set of methods : a) to ensure that at least one of the necessary conditions cannot hold b) to ensure that all of the necessary conditions do not hold c) to decide if the requested resources for a process have to be given or not d) to recover from a deadlock

Effective access time is directly proportional to a) page-fault rate b) hit ratio c) memory access time d) none of the mentioned

Error handler codes, to handle unusual errors are : a) almost never executed b) executed very often c) executed periodically d) None of these

External fragmentation exists when : a) enough total memory exists to satisfy a request but it is not contiguous b) the total memory is insufficient to satisfy a request c) a request cannot be satisfied even when the total memory is free d) None of these

For Mutual exclusion to prevail in the system : a) at least one resource must be held in a non sharable mode b) the processor must be a uniprocessor rather than a multiprocessor c) there must be at least one resource in a sharable mode d) All of these

For every process there is a __________. a) page table b) copy of page table c) pointer to page table d) All of these

For large data transfers, _________ is used. a) DMA b) programmed I/O c) controller register d) None of these

For larger page tables, they are kept in main memory and a __________ points to the page table. a) page table base register b) page table base pointer c) page table register pointer d) page table base

For non sharable resources like a printer, mutual exclusion : a) must exist b) must not exist c) may exist d) None of these

For real time operating systems, interrupt latency should be a) minimal b) maximum c) zero d) dependent on the scheduling

Hard real time operating system has ___ jitter than a soft real time operating system. a) less b) more c) equal d) none of the mentioned

I/O is a _________ in system performance. a) major factor b) minor factor c) does not matter d) None of these

If a disk fails in RAID level ___ rebuilding lost data is easiest. a) 1 b) 2 c) 3 d) 4

If a kernel thread performs a blocking system call, ____________________. a) the kernel can schedule another thread in the application for execution. b) the kernel cannot schedule another thread in the same application for execution. c) the kernel must schedule another thread of a different application for execution. d) the kernel must schedule another thread of the same application on a different processor.

If a page number is not found in the TLB, then it is known as a : a) TLB miss b) buffer miss c) TLB hit d) TLB hit

If a process needs I/O to or from a disk, and if the drive or controller is busy then : a) the request will be placed in the queue of pending requests for that drive b) the request will not be processed and will be ignored completely c) the request will be not be placed d) None of these

If relocation is static and is done at assembly or load time, compaction _________. a) cannot be done b) must be done c) must not be done d) can be done

If the offset is legal : a) it is used as a physical memory address itself b) it is subtracted from the segment base to produce the physical memory address c) it is added to the segment base to produce the physical memory address d) None of these

If the process can be moved during its execution from one memory segment to another, then binding must be : a) delayed until run time b) preponed to compile time c) preponed to load time d) None of these

If the semaphore value is negative : a) its magnitude is the number of processes waiting on that semaphore b) it is invalid c) no operation can be further performed on it until the signal operation is performed on it d) None of these

If there are 32 segments, each of size 1Kb, then the logical address should have : a) 13 bits b) 14 bits c) 15 bits d) 16 bits

If working set window is too small : a) it will not encompass entire locality b) it may overlap several localities c) it will cause memory problems d) None of these

In FIFO page replacement algorithm, when a page must be replaced a) oldest page is chosen b) newest page is chosen c) random page is chosen d) none of the mentioned

In RAID level 4, one block read, accesses __________. a) only one disk b) all disks simultaneously c) all disks sequentially d) None of these

In _______, information is recorded magnetically on platters. a) magnetic disks b) electrical disks c) assemblies d) cylinders

In contiguous memory allocation : a) each process is contained in a single contiguous section of memory b) all processes are contained in a single contiguous section of memory c) the memory space is contiguous d) None of these

In fixed sized partition, the degree of multiprogramming is bounded by ___________. a) the number of partitions b) the CPU utilization c) the memory size d) All of these

In paging the user provides only ________, which is partitioned by the hardware into ________ and ______. a) one address, page number, offset b) one offset, page number, address c) page number, offset, address d) None of these

In polling : a) busy - wait cycles wait for I/O from device b) interrupt handler receives interrupts c) interrupt-request line is triggered by I/O device d) All of these

In rate monotonic scheduling a) shorter duration job has higher priority b) longer duration job has higher priority c) priority does not depend on the duration of the job d) none of the mentioned

In the ______ algorithm, the disk arm goes as far as the final request in each direction, then reverses direction immediately without going to the end of the disk. a) LOOK b) SCAN c) C-SCAN d) C-LOOK

In the bounded buffer problem, there are the empty and full semaphores that : a) count the number of empty and full buffers b) count the number of empty and full memory spaces c) count the number of empty and full queues d) None of these

Multithreading an interactive program will increase responsiveness to the user by : a) continuing to run even if a part of it is blocked b) waiting for one part to finish before the other begins c) asking the user to decide the order of multithreading d) None of these

Mutual exclusion implies that : a) if a process is executing in its critical section, then no other process must be executing in their critical sections b) if a process is executing in its critical section, then other processes must be executing in their critical sections c) if a process is executing in its critical section, then all the resources of the system must be blocked until it finishes execution d) None of these

One way to ensure that the circular wait condition never holds is to : a) impose a total ordering of all resource types and to determine whether one precedes another in the ordering b) to never let a process acquire resources that are held by other processes c) to let a process wait for only one resource at a time d) All of these

Physical memory is broken into fixed-sized blocks called ________. a) frames b) pages c) backing store d) None of these

RAID level 3 supports a lower number of I/Os per second, because _______________. a) every disk has to participate in every I/O request b) only one disk participates per I/O request c) I/O cycle consumes a lot of CPU time d) All of these

RAID level ________ refers to disk arrays with striping at the level of blocks, but without any redundancy. a) 0 b) 1 c) 2 d) 3

Run time mapping from virtual to physical address is done by a) memory management unit b) CPU c) PCI d) none of the mentioned

SSTF algorithm, like SJF __________ of some requests. a) may cause starvation b) will cause starvation c) does not cause starvation d) causes aging

Scheduling is done so as to : a) increase CPU utilization b) decrease CPU utilization c) keep the CPU more idle d) None of these

The Banker's algorithm is _____________ than the resource allocation graph algorithm. a) less efficient b) more efficient c) None of these

The CPU hardware has a wire called __________ that the CPU senses after executing every instruction. a) interrupt request line b) interrupt bus c) interrupt receive line d) interrupt sense line

The _________ are reserved for events such as unrecoverable memory errors. a) nonmaskable interrupts b) blocked interrupts c) maskable interrupts d) None of these

The _________ time in a swap out of a running process and swap in of a new process into the memory is very high. a) context - switch b) waiting c) execution d) All of these

The ___________ must design and program the overlay structure. a) programmer b) system architect c) system designer d) None of these

The algorithm in which we allocate memory to each process according to its size is known as : a) proportional allocation algorithm b) equal allocation algorithm c) split allocation algorithm d) None of the mentioned

The circular wait condition can be prevented by a) defining a linear ordering of resource types b) using thread c) using pipes d) all of the mentioned

The disadvantage of moving all process to one end of memory and all holes to the other direction, producing one large hole of available memory is : a) the cost incurred b) the memory used c) the CPU used d) All of these

The following pair of processes share a common variable X : Process A int Y; A1: Y = X*2; A2: X = Y; Process B int Z; B1: Z = X+1; B2: X = Z; X is set to 5 before either process begins execution. As usual, statements within a process are executed sequentially, but statements in process A may execute in any order with respect to statements in process B. ii) Suppose the programs are modified as follows to use a shared binary semaphore T : Process A int Y; A1: Y = X*2; A2: X = Y; signal(T); Process B int Z; B1: wait(T); B2: Z = X+1; X = Z; T is set to 0 before either process begins execution and, as before, X is set to 5. Now, how many different values of X are possible after both processes finish executing ? a) one b) two c) three d) four

The following program consists of 3 concurrent processes and 3 binary semaphores. The semaphores are initialized as S0 = 1, S1 = 0, S2 = 0. Process P0 while(true) { wait(S0); print '0'; release(S1); release(S2); } Process P1 wait(S1); release(S0); Process P2 wait(S2); release(S0); How many times will P0 print '0' ? a) At least twice b) Exactly twice c) Exactly thrice d) Exactly once

The instruction being executed, must be in : a) physical memory b) logical memory c) None of these

The jacketing technique is used to a) convert a blocking system call into nonblocking system call b) create a new thread c) communicate between threads d) terminate a thread

The maximum number of frames per process is defined by : a) the amount of available physical memory b) Operating System c) instruction set architecture d) None of the mentioned

The minimum number of page frames that must be allocated to a running process in a virtual memory environment is determined by : a) the instruction set architecture b) page size c) physical memory size d) number of processes in memory

The page table contains a) base address of each page in physical memory b) page offset c) page size d) none of the mentioned

The pager concerns with the a) individual page of a process b) entire process c) entire thread d) first page of a process

The portion of the process scheduler in an operating system that dispatches processes is concerned with : a) assigning ready processes to CPU b) assigning ready processes to waiting queue c) assigning running processes to blocked queue d) All of these

The problem of priority inversion can be solved by a) priority inheritance protocol b) priority inversion protocol c) both (a) and (b) d) none of the mentioned

The reason for using the LFU page replacement algorithm is : a) an actively used page should have a large reference count b) a less used page has more chances to be used again c) it is extremely efficient and optimal d) All of the mentioned

The register context and stacks of a thread are deallocated when the thread a) terminates b) blocks c) unblocks d) spawns

The resource allocation graph is not applicable to a resource allocation system : a) with multiple instances of each resource type b) with a single instance of each resource type c) Both a and b

The wait-for graph is a deadlock detection algorithm that is applicable when : a) all resources have a single instance b) all resources have multiple instances c) both a and b

There are 10 different processes running on a workstation. Idle processes are waiting for an input event in the input queue. Busy processes are scheduled with the Round-Robin timesharing method. Which out of the following quantum times is the best value for small response times, if the processes have a short runtime, e.g. less than 10ms ? a) tQ = 15ms b) tQ = 40ms c) tQ = 45ms d) tQ = 50ms

To avoid deadlock a) there must be a fixed number of resources to allocate b) resource allocation must be done only once c) all deadlocked processes must be aborted d) inversion technique can be used

Virtual memory is normally implemented by ________. a) demand paging b) buses c) virtualization d) All of these

VxWorks is centered around a) wind microkernel b) linux kernel c) unix kernel d) none of the mentioned

When a page fault occurs before an executing instruction is complete : a) the instruction must be restarted b) the instruction must be ignored c) the instruction must be completed ignoring the page fault d) None of the mentioned

When a subroutine is called, a) it defines a new locality b) it is in the same locality from where it was called c) it does not define a new locality d) b and c

When memory is divided into several fixed sized partitions, each partition may contain ________. a) exactly one process b) atleast one process c) multiple processes at once d) None of these

When the event for which a thread is blocked occurs, a) thread moves to the ready queue b) thread remains blocked c) thread completes d) a new thread is provided

When the memory allocated to a process is slightly larger than the process, then : a) internal fragmentation occurs b) external fragmentation occurs c) both a and b d) neither a nor b

When using counters to implement LRU, we replace the page with the : a) smallest time value b) largest time value c) greatest size d) None of the mentioned

Which file is a sequence of bytes organized into blocks understandable by the system's linker? a) object file b) source file c) executable file d) text file

Which hardware triggers some operation after certain programmed count? a) programmable interval timer b) interrupt timer c) programmable timer d) none of the mentioned

Which one of the following connects high-speed high-bandwidth device to memory subsystem and CPU. a) expansion bus b) PCI bus c) SCSI bus d) none of the mentioned

With relocation and limit registers, each logical address must be _______ the limit register. a) less than b) equal to c) greater than d) None of these

With round robin scheduling algorithm in a time shared system, a) using very large time slices converts it into First come First served scheduling algorithm b) using very small time slices converts it into First come First served scheduling algorithm c) using extremely small time slices increases performance d) using very small time slices converts it into Shortest Job First algorithm

file system fragmentation occurs when a) unused space or single file are not contiguous b) used space is not contiguous c) unused space is non-contiguous d) multiple files are non-contiguous

Caching : (choose all that apply) a) holds a copy of the data b) is fast memory c) holds the only copy of the data d) holds output for a device

Each entry in a Translation look-aside buffer (TLB) consists of : a) key b) value c) bit value d) constant

In segmentation, each address is specified by : a) a segment number b) an offset c) a value d) a key

In the stack implementation of the LRU algorithm, a stack can be maintained in a manner : a) whenever a page is used, it is removed from the stack and put on top b) the bottom of the stack is the LRU page c) the top of the stack contains the LRU page and all new pages are added to the top d) None of the mentioned

Swap space is allocated : a) as a chunk of disk b) separate from a file system c) into a file system d) All of these

The scheme used in the above question is known as _______ or ________. a) sector sparing b) forwarding c) backwarding d) sector utilization

The technique of duplicating every disk is known as : a) mirroring b) shadowing c) redundancy d) scheduling

Virtual memory allows : a) execution of a process that may not be completely in memory b) a program to be larger than the physical memory c) a program to be larger than the secondary storage d) execution of a process without being in physical memory

The data structue for a sector typically contains : (choose all that apply) a) header b) data area c) trailer d) main section

ABC

The process to be aborted is chosen on the basis of the following factors : (choose all that apply) a) priority of the process b) process is interactive or batch c) how long the process has computed d) how much more long before its completion e) how many more resources the process needs before its completion f) how many and what type of resources the process has used g) how many resources are available in the system h) All of these

ABCDEF

The ability to execute a program that is only partially in memory has benefits like : (choose all that apply) a) the amount of physical memory cannot put a constraint on the program b) programs for an extremely large virtual space can be created c) CPU utilization decreases d) Throughput increases e) response time is not affected f) turnaround time increases g) less I/O will be needed to load or swap each user program in memory h) All of these

ABDEG

A binary semaphore is a semaphore with integer values : (choose two) a) 1 b) -1 c) 0 d) 0.5

Cost factors of process termination include : (choose all that apply) a) number of resources the deadlock process is holding b) CPU utilization at the time of deadlock c) amount of time a deadlocked process has thus far consumed during its execution d) All of the above

Each entry in a segment table has a : a) segment base b) segment peak c) segment limit d) segment value

Every time a request for allocation cannot be granted immediately, the detection algorithm is invoked. This will help identify : (choose all that apply) a) the set of processes that have been deadlocked b) the set of processes in the deadlock queue c) the specific process that caused the deadlock d) All of these

In a system that does not support swapping, a) the compiler normally binds symbolic addresses (variables) to relocatable addresses b) the compiler normally binds symbolic addresses to physical addresses c) the loader binds relocatable addresses to physical addresses d) binding of symbolic addresses to physical addresses normally takes place during execution

In general the two interrupt request lines are : a) nonmaskable interrupt b) blocked interrupt c) maskable interrupt d) None of these

The main memory accommodates : a) operating system b) CPU c) user processes d) All of these

The two methods how LRU page replacement policy can be implemented in hardware are : (choose two) a) Counters b) RAM c) Stack d) Registers

The two ways of aborting processes and eliminating deadlocks are : (choose all that apply) a) Abort all deadlocked processes b) Abort all processes c) Abort one process at a time until the deadlock cycle is eliminated d) All of these

The valid - invalid bit, in this case, when valid indicates : a) the page is legal b) the page is illegal c) the page is in memory d) the page is not in memory

Each request requires that the system consider the __________, _____________, ____________ to decide whether the current request can be satisfied or must wait to avoid a future possible deadlock. (choose three) a) resources currently available b) processes that have previously been in the system c) resources currently allocated to each process d) future requests and releases of each process

ACD

For a deadlock to arise, which of the following conditions must hold simultaneously ? ( choose all that apply ) a) Mutual exclusion b) Starvation c) Hold and wait d) No preemption e) Circular wait

ACDE

A deadlock can be broken by : (choose all that apply) a) abort one or more processes to break the circular wait b) abort all the process in the system c) preempt all resources from all processes d) to preempt some resources from one or more of the deadlocked processes

The two steps the operating system takes to use a disk to hold its files are _______ and ________. a) partitioning b) swap space creation c) caching d) logical formatting

A block device transfers : a) bytes one by one b) block of bytes as a unit c) with unpredictable response times d) None of these

A deadlock eventually cripples system throughput and will cause the CPU utilization to ______. a) increase b) drop c) stay still d) None of these

A deadlock free solution to the dining philosophers problem : a) necessarily eliminates the possibility of starvation b) does not necessarily eliminate the possibility of starvation c) eliminates any possibility of any kind of problem further d) None of these

A heavy weight process : a) has multiple threads of execution b) has a single thread of execution c) can have multiple or a single thread for execution d) None of these

A memory buffer used to accommodate a speed differential is called a) stack pointer b) cache c) accumulator d) disk buffer

A minimum of _____ variable(s) is/are required to be shared between processes to solve the critical section problem. a) one b) two c) three d) four

A multilevel page table is preferred in comparison to a single level page table for translating virtual address to physical address because : a) it reduces the memory access time to read or write a memory location b) it helps to reduce the size of page table needed to implement the virtual address space of a process c) it is required by the translation look aside buffer d) it helps to reduce the number of page faults in page replacement algorithms

A non blocking system call _________________. a) halts the execution of the application for an extended time b) does not halt the execution of the application c) does not block the interrupts d) None of these

A page fault occurs when : a) a page gives inconsistent data b) a page cannot be accesses due to its absence from memory c) a page is invisible d) All of these

A process is thrashing if : a) it spends a lot of time executing, rather than paging b) it spends a lot of time paging, than executing c) it has no memory allocated to it d) None of these

A process refers to 5 pages, A, B, C, D, E in the order : A, B, C, D, A, B, E, A, B, C, D, E. If the page replacement algorithm is FIFO, the number of page transfers with an empty internal store of 3 frames is : In question 2, if the number of page frames is increased to 4, then the number of page transfers : a) decreases b) increases c) remains the same d) None of these

A situation where several processes access and manipulate the same data concurrently and the outcome of the execution depends on the particular order in which access takes place is called : a) data consistency b) race condition c) aging d) starvation

A state is safe, if : a) the system does not crash due to deadlock occurrence b) the system can allocate resources to each process in some order and still avoid a deadlock c) the state keeps the system protected and safe d) All of these

A system with 5 processes P0 through P4 and three resource types A, B, C has A with 10 instances, B with 5 instances, and C with 7 instances. At time t0, the following snapshot has been taken : Process P0 P1 P2 P3 P4 Allocation (process-wise : P0 through P4 top to bottom) A B C 0 1 0 2 0 0 3 0 2 2 1 1 0 0 2 Max (process-wise : P0 through P4 top to bottom) A B C 7 5 3 3 2 2 9 0 2 2 2 2 4 3 3 Available A B C 3 3 2 The sequence leads the system to : a) an unsafe state b) a safe state c) a protected state d) a deadlock

An I/O port typically consists of four registers status, control, ________ and ________ registers. a) system in, system out b) data in, data out c) flow in, flow out d) input, output

An ______ uniquely identifies processes and is used to provide address space protection for that process. a) address space locator b) address space identifier c) address process identifier d) None of these

At a particular time of computation the value of a counting semaphore is 7.Then 20 P operations and 15 V operations were completed on this semaphore.The resulting value of the semaphore is : (GATE 1987) a) 42 b) 2 c) 7 d) 12

Because the kernel thread management is done by the Operating System itself : a) kernel threads are faster to create than user threads b) kernel threads are slower to create than user threads c) kernel threads are easier to manage as well as create then user threads d) None of these

Consider a disk queue with requests for I/O to blocks on cylinders : 98 183 37 122 14 124 65 67 ii) Considering SSTF (shortest seek time first) scheduling, the total number of head movements is, if the disk head is initially at 53 : a) 224 b) 236 c) 245 d) 240

Consider a machine in which all memory reference instructions have only one memory address, for them we need atleast _____ frame(s). a) one b) two c) three d) None of the mentioned

Consider the following page reference string : 1 2 3 4 2 1 5 6 2 1 2 3 7 6 3 2 1 2 3 6 vi) For Optimal page replacement algorithms with 5 frames, the number of page faults is : a) 6 b) 7 c) 10 d) 9

Consider the following set of processes, the length of the CPU burst time given in milliseconds : Process Burst time P1 6 P2 8 P3 7 P4 3 Assuming the above process being scheduled with the SJF scheduling algorithm : a) The waiting time for process P4 is 3ms. b) The waiting time for process P4 is 0ms. c) The waiting time for process P4 is 16ms. d) The waiting time for process P4 is 9ms.

Division by zero, accessing a protected or non existent memory address, or attempting to execute a privileged instruction from user mode are all categorized as ________. a) errors b) exceptions c) interrupt handlers d) All of these

Dynamic loading is : a) loading multiple routines dynamically b) loading a routine only when it is called c) loading multiple routines randomly d) None of these

For 3 page frames, the following is the reference string : 7 0 1 2 0 3 0 4 2 3 0 3 2 1 2 0 1 7 0 1 ii) How many page faults does the FIFO page replacement algorithm produce ? a) 10 b) 15 c) 11 d) 12

For a Hold and wait condition to prevail : a) A process must be not be holding a resource, but waiting for one to be freed, and then request to acquire it b) A process must be holding at least one resource and waiting to acquire additional resources that are being held by other processes c) A process must hold at least one resource and not be waiting to acquire additional resources d) None of these

For most computers, the bootstrap is stored in ____. a) RAM b) ROM c) cache d) tertiary storage

For sharable resources, mutual exclusion : a) is required b) is not required c) None of these

If deadlocks occur frequently, the detection algorithm must be invoked ________. a) rarely b) frequently c) None of these

If no cycle exists in the resource allocation graph : a) then the system will not be in a safe state b) then the system will be in a safe state c) either a or b d) None of these

If no frames are free, _____ page transfer(s) is/are required. a) one b) two c) three d) four

If one thread opens a file with read privileges then a) other threads in the another process can also read from that file b) other threads in the same process can also read from that file c) any other thread can not read from that file d) all of the mentioned

If the number of cycles spent busy - waiting is not excessive, then : a) interrupt driven I/O is more efficient than programmed I/O b) programmed I/O is more efficient than interrupt driven I/O c) Both programmed and interrupt driven I/O are equally efficient d) None of these

If the swap space is simply a large file, within the file system, ____________ used to create it, name it and allocate its space. a) special routines must be b) normal file system routines can be c) normal file system routines cannot be d) swap space storage manager is

If the wait for graph contains a cycle : a) then a deadlock does not exist b) then a deadlock exists c) then the system is in a safe state d) either b or c

If we preempt a resource from a process, the process cannot continue with its normal execution and it must be : a) aborted b) rolled back c) terminated d) queued

If working set window is too large : a) it will not encompass entire locality b) it may overlap several localities c) it will cause memory problems d) None of these

In paged memory systems, if the page size is increased, then the internal fragmentation generally : a) becomes less b) becomes more c) remains constant d) None of these

In real time operating system a) all processes have the same priority b) a task must be serviced by its deadline period c) process scheduling can be done only once d) kernel is not required

In the ______ algorithm, the disk arm starts at one end of the disk and moves toward the other end, servicing requests till the other end of the disk. At the other end, the direction is reversed and servicing continues. a) LOOK b) SCAN c) C-SCAN d) C-LOOK

In the bakery algorithm to solve the critical section problem : a) each process is put into a queue and picked up in an ordered manner b) each process receives a number (may or may not be unique) and the one with the lowest number is served next c) each process gets a unique number and the one with the highest number is served next d) each process gets a unique number and the one with the lowest number is served next

In the bounded buffer problem : a) there is only one buffer b) there are n buffers ( n being greater than one but finite) c) there are infinite buffers d) the buffer size is bounded

In virtual memory. the programmer __________ of overlays. a) has to take care b) does not have to take care c) None of these

In which scheduling certain amount of CPU time is allocated to each process? a) earliest deadline first scheduling b) proportional share scheduling c) equal share scheduling d) none of the mentioned

LRU page - replacement algorithm associates with each page the ______ a) time it was brought into memory b) the time of that page's last use c) page after and before it d) All of these

Logical memory is broken into blocks of the same size called _________. a) frames b) pages c) backing store d) None of these

Magnetic tape drives can write data at a speed ________ disk drives. a) much lesser than b) comparable to c) much faster than d) None of these

Memory management technique in which system stores and retrieves data from secondary storage for use in main memory is called a) fragmentation b) paging c) mapping d) none of the mentioned

Multithreaded programs are : a) lesser prone to deadlocks b) more prone to deadlocks c) not at all prone to deadlocks d) None of these

Optimal page - replacement algorithm is difficult to implement, because : a) it requires a lot of information b) it requires future knowledge of the reference string c) it is too complex d) it is extremely expensive

RAID level 0+1 is used because, RAID level 0 provides ______ whereas RAID level 1 provides ________. a) performance, redundancy b) performance, reliability c) redundancy, performance d) None of these

RAID level ______ is also known as memory style error correcting code(ECC) organization. a) 1 b) 2 c) 3 d) 4

Round robin scheduling falls under the category of : a) Non preemptive scheduling b) Preemptive scheduling c) None of these

Semaphores are mostly used to implement : a) System calls b) IPC mechanisms c) System protection d) None of these

Sometimes the overhead of keeping track of a hole might be : a) larger than the memory b) larger than the hole itself c) very small d) All of these

Spinlocks are intended to provide __________ only. a) Mutual Exclusion b) Bounded Waiting c) Aging d) Progress

Swap space exists in a) primary memory b) secondary memory c) CPU d) none of the mentioned

The FCFS algorithm is particularly troublesome for ____________. a) time sharing systems b) multiprogramming systems c) multiprocessor systems d) Operating systems

The FIFO algorithm : a) first executes the job that came in last in the queue b) first executes the job that came in first in the queue c) first executes the job that needs minimal processor d) first executes the job that has maximum processor needs

The ________ consists of all processes whose memory images are in the backing store or in memory and are ready to run. a) wait queue b) ready queue c) CPU d) secondary storage

The __________ is used as an index into the page table. a) frame bit b) page number c) page offset d) frame offset

The accuracy of the working set depends on the selection of : a) working set model b) working set size c) memory size d) number of pages in memory

The address generated by the CPU is referred to as : a) physical address b) logical address c) Neither a nor b

The address of a page table in memory is pointed by a) stack pointer b) page table base register c) page register d) program counter

The advantage of dynamic loading is that : a) a used routine is used multiple times b) an unused routine is never loaded c) CPU utilization increases d) All of these

The algorithm in which we split m frames among n processes, to give everyone an equal share, m/n frames is known as : a) proportional allocation algorithm b) equal allocation algorithm c) split allocation algorithm d) None of the mentioned

The disadvantage of a process being allocated all its resources before beginning its execution is : a) Low CPU utilization b) Low resource utilization c) Very high resource utilization d) None of these

The essential content(s) in each entry of a page table is / are : a) Virtual page number b) Page frame number c) Both virtual page number and page frame number d) Access right information

The hardware mechanism that allows a device to notify the CPU is called _______. a) polling b) interrupt c) driver d) controlling

The heads of the magnetic disk are attached to a _____ that moves all the heads as a unit. a) spindle b) disk arm c) track d) None of these

The host controller is : a) controller built at the end of each disk b) controller at the computer end of the bus c) both a and b d) neither a nor b

The interrupt vector contains : a) the interrupts b) the memory addresses of specialized interrupt handlers c) the identifiers of interrupts d) the device addresses

The kernel data structures include : a) process table b) open file table c) close file table d) All of these

The main disadvantage of spinlocks is that : a) they are not sufficient for many process b) they require busy waiting c) they are unreliable sometimes d) they are too complex for programmers

The major part of swap time is _______ time. a) waiting b) transfer c) execution d) None of these

The page table registers should be built with _______. a) very low speed logic b) very high speed logic c) a large memory space d) None of these

The percentage of times a page number is found in the TLB is known as : a) miss ratio b) hit ratio c) miss percent d) None of these

The real difficulty with SJF in short term scheduling is : a) it is too good an algorithm b) knowing the length of the next CPU request c) it is too complex to understand d) None of these

The reason for using the MFU page replacement algorithm is : a) an actively used page should have a large reference count b) a less used page has more chances to be used again c) it is extremely efficient and optimal d) All of the mentioned

The run time mapping from virtual to physical addresses is done by a hardware device called the : a) Virtual to physical mapper b) memory management unit c) memory mapping unit d) None of these

The segment base contains the : a) starting logical address of the process b) starting physical address of the segment in memory c) segment length d) None of these

The strategy of making processes that are logically runnable to be temporarily suspended is called : a) Non preemptive scheduling b) Preemptive scheduling c) Shortest job first d) First come First served

The time required to create a new thread in an existing process is a) greater than the time required to create a new process c) less than the time required to create a new process c) equal to the time required to create a new process d) none of the mentioned

The wait operation of the semaphore basically works on the basic _______ system call. a) stop() b) block() c) hold() d) wait()

There is a set of page replacement algorithms that can never exhibit Belady's Anomaly, called : a) queue algorithms b) stack algorithms c) string algorithms d) None of the mentioned

Those processes should be aborted on occurrence of a deadlock, the termination of which : a) is more time consuming b) incurs minimum cost c) safety is not hampered d) All of these

Time duration required for scheduling dispatcher to stop one process and start another is known as a) process latency b) dispatch latency c) execution latency d) interrupt latency

To _______ to a safe state, the system needs to keep more information about the states of processes. a) abort the process b) roll back the process c) queue the process d) None of these

To ensure difficulties do not arise in the readers - writers problem, _______ are given exclusive access to the shared object. a) readers b) writers c) None of these

Transient operating system code is code that : a) is not easily accessible b) comes and goes as needed c) stays in the memory always d) never enters the memory space

Under multiprogramming, turnaround time for short jobs is usually ________ and that for long jobs is slightly ___________. a) Lengthened; Shortened b) Shortened; Lengthened c) Shortened; Shortened d) Shortened; Unchanged

Users _______ that their processes are running on a paged system. a) are aware b) are unaware c) None of these

Using swap space significantly _________ system performance. a) increases b) decreases c) maintains d) does not affect

Virtual memory uses disk space as an extension of _________. a) secondary storage b) main memory c) tertiary storage d) None of these

What will happen if a non-recursive mutex is locked more than once ? a) Starvation b) Deadlock c) Aging d) Signaling

When a process begins execution with no pages in memory : a) process execution becomes impossible b) a page fault occurs for every page brought into memory c) process causes system crash d) None of these

When device A has a cable that plugs into device B, and device B has a cable that plugs into device C and device C plugs into a port on the computer, this arrangement is called a _________. a) port b) daisy chain c) bus d) cable

Whenever a process needs I/O to or from a disk it issues a ______________. a) system call to the CPU b) system call to the operating system c) a special procedure d) All of these

Which of the following algorithms tends to minimize the process flow time ? a) First come First served b) Shortest Job First c) Earliest Deadline First d) Longest Job First

Which of the following scheduling algorithms gives minimum average waiting time ? a) FCFS b) SJF c) Round - robin d) Priority

Which one of the following explains the sequential file access method? a) random access according to the given byte number b) read bytes one at a time, in order c) read/write sequentially by record d) read/write randomly by record

Which one of the following is not a valid state of a thread? a) running b) parsing c) ready d) blocked

With either equal or proportional algorithm, a high priority process is treated ___________ a low priority process. a) greater than b) same as c) lesser than d) None of the mentioned

With paging there is no ________ fragmentation. a) internal b) external c) either type of d) None of these

Working set model for page replacement is based on the assumption of a) modularity b) locality c) globalization d) random access

_____ is the concept in which a process is copied into main memory from the secondary memory according to the requirement. a) Paging b) Demand paging c) Segmentation d) Swapping

A disk that has a boot partition is called a _________. (choose all that apply) a) start disk b) system disk c) boot disk d) All of these

Every address generated by the CPU is divided into two parts : (choose two) a) frame bit b) page number c) page offset d) frame offset

The idea of overlays is to : (choose all that apply) a) enable multiple processes execute at once b) enable a process to be larger than the amount of memory allocated to it c) keep in memory only those instructions and data that are needed at any given time d) All of these

The protection bit is 0/1 based on : (choose all that apply) a) write only b) read only c) read - write d) None of these

The two kinds of semaphores are : (choose two) a) mutex b) binary c) counting d) decimal

Using a pager : a) increases the swap time b) decreases the swap time c) decreases the amount of physical memory needed d) increases the amount of physical memory needed

When a page is selected for replacement, and its modify bit is set : a) the page is clean b) the page has been modified since it was read in from the disk c) the page is dirty d) a and b

When there is a large logical address space, the best way of paging would be : a) not to page b) a two level paging algorithm c) to page the page table itself d) All of these

The following three conditions must be satisfied to solve the critical section problem : (choose three) a) Aging b) Mutual Exclusion c) Deadlock d) Progress e) Bounded Waiting

BDE

A ____ a set of wires and a rigidly defined protocol that specifies a set of messages that can be sent on the wires. a) port b) node c) bus d) None of these

A keyboard is an example of a device that is accessed through a __________ interface. a) block stream b) set of blocks c) character stream d) None of these

A large number of disks in a system improves the rate at which data can be read or written : a) if the disks are operated on sequentially b) if the disks are operated on selectively c) if the disks are operated in parallel d) All of these

A memory page containing a heavily used variable that was initialized very early and is in constant use is removed, then the page replacement algorithm used is : a) LRU b) LFU c) FIFO d) None of these

A process can be a) single threaded b) multithreaded c) both (a) and (b) d) none of the mentioned

A semaphore : a) is a binary mutex b) must be accessed from only one process c) can be accessed from multiple processes d) None of these

A swapper manipulates ___________, whereas the pager is concerned with individual _______ of a process. a) the entire process, parts b) all the pages of a process, segments c) the entire process, pages d) None of these

A system is in a safe state only if there exists a : a) safe allocation b) safe resource c) safe sequence d) All of these

A system is in the safe state if a) the system can allocate resources to each process in some order and still avoid a deadlock b) there exist a safe sequence c) both (a) and (b) d) none of the mentioned

A thread shares its resources(like data section, code section, open files, signals) with : a) other process similar to the one that the thread belongs to b) other threads that belong to similar processes c) other threads that belong to the same process d) All of these

A virtual memory system uses First In First Out (FIFO) page replacement policy and allocates a fixed number of frames to a process. Consider the following statements : P : Increasing the number of page frames allocated to a process sometimes increases the page fault rate Q : Some programs do not exhibit locality of reference Which of the following is TRUE? a) Both P and Q are true, and Q is the reason for P b) Both P and Q are true, but Q is not the reason for P c) P is false but Q is true d) Both P and Q are false

All processes share a semaphore variable mutex, initialized to 1. Each process must execute wait(mutex) before entering the critical section and signal(mutex) afterward. i) Suppose a process executes in the following manner : signal(mutex); ..... critical section ..... wait(mutex); In this situation : a) a deadlock will occur b) processes will starve to enter critical section c) several processes maybe executing in their critical section d) All of these

Applying the LRU page replacement to the following reference string : 1 2 4 5 2 1 2 4 The main memory can accommodate 3 pages and it already has pages 1 and 2. Page 1 came in before page 2. How many page faults will occur ? a) 2 b) 3 c) 4 d) 5

Concurrent access to shared data may result in : a) data consistency b) data insecurity c) data inconsistency d) None of these

Consider a computer with 8 Mbytes of main memory and a 128 K cache. The cache block size is 4 K. It uses a direct mapping scheme for cache management. How many different main memory blocks can map onto a given physical cache block ? a) 2048 b) 256 c) 64 d) 8

Consider the following page reference string : 1 2 3 4 2 1 5 6 2 1 2 3 7 6 3 2 1 2 3 6 ii) For LRU page replacement algorithm with 5 frames, the number of page faults is : a) 10 b) 14 c) 8 d) 11

Consider the following page reference string : 1 2 3 4 2 1 5 6 2 1 2 3 7 6 3 2 1 2 3 6 iv) For FIFO page replacement algorithms with 4 frames, the number of page faults is : a) 16 b) 15 c) 14 d) 11

Consider the following set of processes, the length of the CPU burst time given in milliseconds : Process Burst time P1 6 P2 8 P3 7 P4 3 ii) Assuming the above process being scheduled with the SJF scheduling algorithm : a) The waiting time for process P2 is 3ms. b) The waiting time for process P2 is 0ms. c) The waiting time for process P2 is 16ms. d) The waiting time for process P2 is 9ms.

Each process Pi, i = 0,1,2,3,......,9 is coded as follows : repeat P(mutex) {Critical Section} V(mutex) forever The code for P10 is identical except that it uses V(mutex) instead of P(mutex). What is the largest number of processes that can be inside the critical section at any moment (the mutex being initialized to 1)? a) 1 b) 2 c) 3 d) None of these

For effective operating system, when to check for deadlock? a) every time a resource request is made b) at fixed time intervals c) both (a) and (b) d) none of the mentioned

Given a priori information about the ________ number of resources of each type that maybe requested for each process, it is possible to construct an algorithm that ensures that the system will never enter a deadlock state. a) minimum b) average c) maximum d) approximate

If a higher priority process arrives and wants service, the memory manager can swap out the lower priority process to execute the higher priority process. When the higher priority process finishes, the lower priority process is swapped back in and continues execution. This variant of swapping is sometimes called : a) priority swapping b) pull out, push in c) roll out, roll in d) None of these

If binding is done at assembly or load time, then the process _____ be moved to different locations after being swapped out and in again. a) can b) must c) can never d) may

If the kernel is single threaded, then any user level thread performing a blocking system call will : a) cause the entire process to run along with the other threads b) cause the thread to block with the other threads running c) cause the entire process to block even if the other threads are available to run d) None of these

In SCSI disks used in high end PCs, the controller maintains a list of _________ on the disk. The disk is initialized during ________ formatting which sets aside spare sectors not visible to the operating system. a) destroyed blocks, high level formatting b) bad blocks, partitioning c) bad blocks, low level formatting d) destroyed blocks, partitioning

In a paged memory, the page hit ratio is 0.35. The required to access a page in secondary memory is equal to 100 ns. The time required to access a page in primary memory is 10 ns. The average time required to access a page is : a) 3.0 ns b) 68.0 ns c) 68.5 ns d) 78.5 ns

In the _______ algorithm, the disk head moves from one end to the other , servicing requests along the way. When the head reaches the other end, it immediately returns to the beginning of the disk without servicing any requests on the return trip. a) LOOK b) SCAN c) C-SCAN d) C-LOOK

In the working set model, for : 2 6 1 5 7 7 7 7 5 1 6 2 3 4 1 2 3 4 4 4 3 4 3 4 4 4 1 3 2 3 if DELTA = 10, then the working set at time t1 (....7 5 1) is : a) {1, 2, 4, 5, 6} b) {2, 1, 6, 7, 3} c) {1, 6, 5, 7, 2} d) {1, 2, 3, 4, 5}

Increasing the RAM of a computer typically improves performance because: a) Virtual memory increases b) Larger RAMs are faster c) Fewer page faults occur d) None of the mentioned

It is __________ to reread a page from the file system than to write it to swap space and then to reread it from there. a) useless b) less efficient c) more efficient d) None of these

On media that use constant linear velocity (CLV), the _____________ is uniform. a) density of bits on the disk b) density of bits per sector c) the density of bits per track d) None of these

One of the disadvantages of the priority scheduling algorithm is that : a) it schedules in a very complex manner b) its scheduling takes up a lot of time c) it can lead to some low priority process waiting indefinitely for the CPU d) None of these

Optimal page - replacement algorithm is : a) Replace the page that has not been used for a long time b) Replace the page that has been used for a long time c) Replace the page that will not be used for a long time d) None of these

Orders are processed in the sequence they arrive if _______ rule sequences the jobs. a) earliest due date b) slack time remaining c) first come, first served d) critical ratio

Paging increases the ______ time. a) waiting b) execution c) context - switch d) All of these

RAID level 3 does not have _________ as in RAID level 1. a) efficiency b) enough storage space for data c) storage overhead d) time consumption overhead

RAID level 5 is also known as : a) bit-interleaved parity organization b) block-interleaved parity organization c) block-interleaved distributed parity d) memory-style ECC organization

Scheduling is done so as to : a) increase the response time b) keep the response time the same c) decrease the response time d) None of these

Segment replacement algorithms are more complex than page replacement algorithms because : a) Segments are better than pages b) Pages are better than segments c) Segments have variable sizes d) Segments have fixed sizes

Semaphore is a/an _______ to solve the critical section problem. a) hardware for a system b) special program for a system c) integer variable d) None of these

Swapping _______ be done when a process has pending I/O, or has to execute I/O operations only into operating system buffers. a) must b) can c) must never d) maybe

Termination of the process terminates a) first thread of the process b) first two threads of the process c) all threads within the process d) no thread within the process

The TestAndSet instruction is executed : a) after a particular process b) periodically c) atomically d) None of these

The _____ table contains the base address of each page in physical memory. a) process b) memory c) page d) frame

The _______ program initializes all aspects of the system, from CPU registers to device controllers and the contents of main memory, and then starts the operating system. a) main b) bootloader c) bootstrap d) ROM

The ________ can be turned off by the CPU before the execution of critical instruction sequences that must not be interrupted. a) nonmaskable interrupt b) blocked interrupt c) maskable interrupt d) None of these

The _________ determines the cause of the interrupt, performs the necessary processing and executes a return from the interrupt instruction to return the CPU to the execution state prior to the interrupt. a) interrupt request line b) device driver c) interrupt handler d) All of these

The _________ present a uniform device-access interface to the I/O subsystem, much as system calls provide a standard interface between the application and the operating system. a) devices b) buses c) device drivers d) I/O systems

The __________ is used by device controllers to request service. a) nonmaskable interrupt b) blocked interrupt c) maskable interrupt d) None of these

The aim of creating page replacement algorithms is to : a) replace pages faster b) increase the page fault rate c) decrease the page fault rate d) to allocate multiple pages to processes

The base register is also known as the : a) basic register b) regular register c) relocation register d) delocation register

The bounded buffer problem is also known as : a) Readers - Writers problem b) Dining - Philosophers problem c) Producer - Consumer problem d) None of these

The code that changes the value of the semaphore is : a) remainder section code b) non - critical section code c) critical section code d) None of these

The content of the matrix Need is : a) Allocation - Available b) Max - Available c) Max - Allocation d) Allocation - Max

The disadvantage of invoking the detection algorithm for every request is : a) overhead of the detection algorithm due to consumption of memory b) excessive time consumed in the request to be allocated memory c) considerable overhead in computation time d) All of these

The disk bandwidth is : a) the total number of bytes transferred b) total time between the first request for service and the completion on the last transfer c) the total number of bytes transferred divided by the total time between the first request for service and the completion on the last transfer d) None of these

The first fit, best fit and worst fit are strategies to select a ______. a) process from a queue to put in memory b) processor to run the next process c) free hole from a set of available holes d) All of these

The host sets _____ bit when a command is available for the controller to execute. a) write b) status c) command-ready d) control

The implementation of the LFU and the MFU algorithm is very uncommon because : a) they are too complicated b) they are optimal c) they are expensive d) All of the mentioned

The kernel is _______ of user threads. a) a part of b) the creator of c) unaware of d) aware of

The mean time to failure of a mirrored disk depends on : I) the mean time to failure of individual disks II) the mean time to repair a) Only I b) Only II c) Both I and II d) Neither I nor II

The minimum number of frames to be allocated to a process is decided by the : a) the amount of available physical memory b) Operating System c) instruction set architecture d) None of the mentioned

The number of resources requested by a process : a) must always be less than the total number of resources available in the system b) must always be equal to the total number of resources available in the system c) must not exceed the total number of resources available in the system d) must exceed the total number of resources available in the system

The operating system is : a) in the low memory b) in the high memory c) either a or b (depending on the location of interrupt vector) d) None of these

The operating system maintains a ______ table that keeps track of how many frames have been allocated, how many are there, and how many are available. a) page b) mapping c) frame d) memory

The overall I/O rate in RAID level 4 is : a) low b) very low c) high d) None of these

The potential overuse of a single parity disk is avoided in RAID level ____. a) 3 b) 4 c) 5 d) All of these

The relocation register helps in : a) providing more address space to processes b) a different address space to processes c) to protect the address spaces of processes d) None of these

The request and release of resources are ___________. a) command line statements b) interrupts c) system calls d) special programs

The time taken to move the disk arm to the desired cylinder is called the : a) positioning time b) random access time c) seek time d) rotational latency

Thrashing _______ the CPU utilization. a) increases b) keeps constant c) decreases d) None of these

Time required to synchronous switch from the context of one thread to the context of another thread is called a) threads fly-back time b) jitter c) context switch time d) none of the mentioned

To create a file a) allocate the space in file system b) make an entry for new file in directory c) both (a) and (b) d) none of the mentioned

Using transient code, _______ the size of the operating system during program execution. a) increases b) decreases c) changes d) maintains

When the valid - invalid bit is set to valid, it means that the associated page : a) is in the TLB b) has data in it c) is in the process's logical address space d) is the system's physical address space

Which algorithm chooses the page that has not been used for the longest period of time whenever the page required to be replaced? a) first in first out algorithm b) additional reference bit algorithm c) least recently used algorithm d) counting based page replacement algorithm

Which of the following is TRUE ? a) Overlays are used to increase the size of physical memory b) Overlays are used to increase the logical address space c) When overlays are used, the size of a process is not limited to the size of the physical memory d) Overlays are used whenever the physical address space is smaller than the logical address space

Which of the following page replacement algorithms suffers from Belady's Anomaly ? a) Optimal replacement b) LRU c) FIFO d) Both optimal replacement and FIFO

Which one of the following is not shared by threads? a) program counter b) stack c) both (a) and (b) d) none of the mentioned

Which one of the following is the address generated by CPU? a) physical address b) absolute address c) logical address d) none of the mentioned

______ controller sends the command placed into it, via messages to the _____ controller. a) host, host b) disk, disk c) host, disk d) disk, host

_________ replacement allows a process to select a replacement frame from the set of all frames, even if the frame is currently allocated to some other process. a) Local b) Universal c) Global d) Public

The process of dividing a disk into sectors that the disk controller can read and write, before a disk can store data is known as : (choose all that apply) a) partitioning b) swap space creation c) low-level formatting d) physical formatting

'Aging' is : a) keeping track of cache contents b) keeping track of what pages are currently residing in memory c) keeping track of how many times a given page is referenced d) increasing the priority of jobs to ensure termination in a finite time

A solution to the problem of indefinite blockage of low - priority processes is : a) Starvation b) Wait queue c) Ready queue d) Aging

A system has 12 magnetic tape drives and 3 processes : P0, P1, and P2. Process P0 requires 10 tape drives, P1 requires 4 and P2 requires 9 tape drives. Process P0 P1 P2 Maximum needs (process-wise : P0 through P2 top to bottom) 10 4 9 Currently allocated (process-wise) 5 2 2 Which of the following sequence is a safe sequence ? a) P0, P1, P2 b) P1, P2, P0 c) P2, P0, P1 d) P1, P0, P2

A write of a block has to access : (choose all that apply) a) the disk on which the block is stored b) parity disk c) a parity block d) All of these

Address Binding is : a) going to an address in memory b) locating an address with the help of another address c) binding two addresses together to form a new address in a different memory space d) a mapping from one address space to another

By using the specific system call, we can a) open the file b) read the file c) write into the file d) all of the mentioned

Consider a disk queue with requests for I/O to blocks on cylinders : 98 183 37 122 14 124 65 67 i) Considering FCFS (first cum first served) scheduling, the total number of head movements is, if the disk head is initially at 53 : a) 600 b) 620 c) 630 d) 640

Consider the following page reference string : 1 2 3 4 2 1 5 6 2 1 2 3 7 6 3 2 1 2 3 6 v) For Optimal page replacement algorithms with 3 frames, the number of page faults is : a) 16 b) 15 c) 14 d) 11

Consider the following set of processes, the length of the CPU burst time given in milliseconds : Process Burst time P1 6 P2 8 P3 7 P4 3 iv) Assuming the above process being scheduled with the SJF scheduling algorithm : a) The waiting time for process P3 is 3ms. b) The waiting time for process P3 is 0ms. c) The waiting time for process P3 is 16ms. d) The waiting time for process P3 is 9ms.

Consider the methods used by processes P1 and P2 for accessing their critical sections whenever needed, as given below. The initial values of shared boolean variables S1 and S2 are randomly assigned. (GATE 2010) Method used by P1 : while(S1==S2); Critical section S1 = S2; Method used by P2 : while(S1!=S2); Critical section S2 = not(S1); Which of the following statements describes properties achieved ? a) Mutual exclusion but not progress b) Progress but not mutual exclusion c) Neither mutual exclusion nor progress d) Both mutual exclusion and progress

Device drivers are implemented to interface a) character devices b) block devices c) network devices d) all of the mentioned

External fragmentation will not occur when : a) first fit is used b) best fit is used c) worst fit is used d) no matter which algorithm is used, it will always occur

For 3 page frames, the following is the reference string : 7 0 1 2 0 3 0 4 2 3 0 3 2 1 2 0 1 7 0 1 i) How many page faults does the LRU page replacement algorithm produce ? a) 10 b) 15 c) 11 d) 12

For swap space created in a seperate disk partition where no file system or directory structure is placed, _____________ used to allocate and deallocate the blocks. a) special routines must be b) normal file system routines can be c) normal file system routines cannot be d) swap space storage manager is

I/O hardware contains a) bus b) controller c) I/O port and its registers d) all of the mentioned

If execution time binding is being used, then a process ______ be swapped to a different memory space. a) has to be b) can never c) must d) may

If one or more devices use a common set of wires to communicate with the computer system, the connection is called ______. a) CPU b) Monitor c) wirefull d) bus

If the mean time to failure of a single disk is 100,000 hours, then the mean time to failure of some disk in an array of 100 disks will be : a) 100 hours b) 10 days c) 10 hours d) 1000 hours

If the size of logical address space is 2 to the power of m, and a page size is 2 to the power of n addressing units, then the high order _____ bits of a logical address designate the page number, and the ____ low order bits designate the page offset. a) m, n b) n, m c) m - n, m d) m - n, n

Memory protection in a paged environment is accomplished by : a) protection algorithm with each page b) restricted access rights to users c) restriction on page visibility d) protection bit with each page

One problem with the global replacement algorithm is that : a) it is very expensive b) many frames can be allocated to a process c) only a few frames can be allocated to a process d) a process cannot control its own page - fault rate

Preemptive Shortest Job First scheduling is sometimes called : a) Fast SJF scheduling b) EDF scheduling - Earliest Deadline First c) HRRN scheduling - Highest Response Ratio Next d) SRTN scheduling - Shortest Remaining Time Next

RAID level _____ is also known as block interleaved parity organisation and uses block level striping and keeps a parity block on a seperate disk. a) 1 b) 2 c) 3 d) 4

RAID level ______ is also known as bit interleaved parity organisation. a) 0 b) 1 c) 2 d) 3

RAID stands for : a) Redundant Allocation of Inexpensive Disks b) Redundant Array of Important Disks c) Redundant Allocation of Independent Disks d) Redundant Array of Independent Disks

Random access in magnetic tapes is _________, compared to magnetic disks. a) fast b) very fast c) slow d) very slow

Resource sharing helps : a) share the memory and resources of the process to which the threads belong. b) an application have several different threads of activity all within the same address space c) reduce the address space that a process could potentially use d) All of these

Spinlocks are : a) CPU cycles wasting locks over critical sections of programs b) locks that avoid time wastage in context switches c) locks that work better on multiprocessor systems d) All of these

The ______ register is written by the host to send output. a) status b) control c) data in d) data out

The backing store is generally a : (choose all that apply) a) fast disk b) disk large enough to accommodate copies of all memory images for all users c) disk to provide direct access to the memory images d) All of these

The operating system and the other processes are protected from being modified by an already running process because : a) they are in different memory spaces b) they are in different logical addresses c) they have a protection algorithm d) every address generated by the CPU is being checked against the relocation and limit registers

The set of tracks that are at one arm position make up a ___________. a) magnetic disks b) electrical disks c) assemblies d) cylinders

The time taken for the desired sector to rotate to the disk head is called : a) positioning time b) random access time c) seek time d) rotational latency

Thread synchronization is required because a) all threads of a process share the same address space b) all threads of a process share the same global variables c) all threads of a process can share the same files d) all of the mentioned

Time taken in memory access through PTBR is : a) extended by a factor of 3 b) extended by a factor of 2 c) slowed by a factor of 3 d) slowed by a factor of 2

To ensure no preemption, if a process is holding some resources and requests another resource that cannot be immediately allocated to it : a) then the process waits for the resources be allocated to it b) the process keeps sending requests until the resource is allocated to it c) the process resumes execution without the resource being allocated to it d) then all resources currently being held are preempted

To ensure that the hold and wait condition never occurs in the system, it must be ensured that : a) whenever a resource is requested by a process, it is not holding any other resources b) each process must request and be allocated all its resources before it begins its execution c) a process can request resources only when it has none d) All of these

To obtain better memory utilization, dynamic loading is used. With dynamic loading, a routine is not loaded until it is called. For implementing dynamic loading, a) special support from hardware is required b) special support from operating system is essential c) special support from both hardware and operating system is essential d) user programs can implement dynamic loading without any special support from hardware or operating system

Two processes, P1 and P2, need to access a critical section of code. Consider the following synchronization construct used by the processes : Process P1 : while(true) { w1 = true; while(w2 == true); Critical section w1 = false; } Remainder Section Process P2 : while(true) { w2 = true; while(w1 == true); Critical section w2 = false; } Remainder Section Here, w1 and w2 are shared variables, which are initialized to false. Which one of the following statements is TRUE about the above construct? a) It does not ensure mutual exclusion b) It does not ensure bounded waiting c) It requires that processes enter the critical section in strict alternation d) It does not prevent deadlocks, but ensures mutual exclusion

When hardware is accessed by reading and writing to the specific memory locations, then it is called a) port-mapped I/O b) controller-mapped I/O c) bus-mapped I/O d) none of the mentioned

Where performance and reliability are both important, RAID level ____ is used. a) 0 b) 1 c) 2 d) 0+1

Which of the following condition is required for deadlock to be possible? a) mutual exclusion b) a process may hold allocated resources while awaiting assignment of other resources c) no resource can be forcibly removed from a process holding it d) all of the mentioned

Which of the following is FALSE ? (GATE 2007) a) Context switch time is longer for kernel level threads than for user level threads b) User level threads do not need any hardware support c) Related kernel level threads can be scheduled on different processors in a multiprocessor system d) Blocking one kernel level thread blocks all other related threads

Which of the following statements are true ? (GATE 2010) I. Shortest remaining time first scheduling may cause starvation II. Preemptive scheduling may cause starvation III. Round robin is better than FCFS in terms of response time a) I only b) I and III only c) II and III only d) I, II and III

Which of the following statements are true ? (GATE 2010) i) Shortest remaining time first scheduling may cause starvation ii) Preemptive scheduling may cause starvation iii) Round robin is better than FCFS in terns of response time a) i only b) i and iii only c) ii and iii only d) i, ii and iii

Which one of the following is a real time operating system? a) RTLinux b) VxWorks c) windows CE d) all of the mentioned

An un-interruptible unit is known as : a) single b) atomic c) static d) None of these

The segment limit contains the : a) starting logical address of the process b) starting physical address of the segment in memory c) segment length d) None of these

The solution to the problem of reliability is the introduction of __________. a) aging b) scheduling c) redundancy d) disks

Defective sectors on disks are often known as __________. a) good blocks b) destroyed blocks c) bad blocks d) None of these

A ________ is a full duplex connection between a device driver and a user level process. a) bus b) I/O operation c) stream d) flow

RAID level ____ spreads parity and data among all N+1 disks rather than storing data in N disks and parity in 1. a) 3 b) 4 c) 5 d) 6

A character stream device transfers : a) bytes one by one b) block of bytes as a unit c) with unpredictable response times d) None of these

A program is generally composed of several different localities, which _____ overlap. a) may b) must c) do not d) must not

Spooling : (choose all that apply) a) holds a copy of the data b) is fast memory c) holds the only copy of the data d) holds output for a device

The size of a page is typically : a) varied b) power of 2 c) power of 4 d) None of these

Scheduling is : a) allowing a job to use the processor b) making proper use of processor c) Both a and b d) None of these

In multilevel feedback scheduling algorithm a) a process can move to a different classified ready queue b) classification of ready queue is permanent c) processes are not classified into groups d) none of the mentioned

The link between two processes P and Q to send and receive messages is called : a) communication link b) message-passing link c) synchronization link d) All of these

Which process can be affected by other processes executing in the system? a) cooperating process b) child process c) parent process d) init process

Which scheduling algorithm allocates the CPU first to the process that requests the CPU first? a) first-come, first-served scheduling b) shortest job scheduling c) priority scheduling d) none of the mentioned

A monitor is a module that encapsulates a) shared data structures b) procedures that operate on shared data structure c) synchronization between concurrent procedure invocation d) all of the mentioned

A process can be terminated due to a) normal exit b) fatal error c) killed by another process d) all of the mentioned

In operating system, each process has its own a) address space and global variables b) open files c) pending alarms, signals and signal handlers d) all of the mentioned

The context of a process in the PCB of a process does not contain : a) the value of the CPU registers b) the process state c) memory-management information d) context switch time

The state of a process is defined by : a) the final activity of the process b) the activity just executed by the process c) the activity to next be executed by the process d) the current activity of the process

What is operating system? a) collection of programs that manages hardware resources b) system service provider to the application programs c) link to interface the hardware and application programs d) all of the mentioned

The two steps of a process execution are : (choose two) a) I/O Burst b) CPU Burst c) Memory Burst d) OS Burst

The objective of multi-programming is to : (choose two) a) Have some process running at all times b) Have multiple programs waiting in a queue ready to run c) To minimize CPU utilization d) To maximize CPU utilization

In priority scheduling algorithm, when a process arrives at the ready queue, its priority is compared with the priority of a) all process b) currently running process c) parent process d) init process

In the non blocking send : a) the sending process keeps sending until the message is received b) the sending process sends the message and resumes operation c) the sending process keeps sending until it receives a message d) None of these

Response time is : a) the total time taken from the submission time till the completion time b) the total time taken from the submission time till the first response is produced c) the total time taken from submission time till the response is output d) None of these

The interval from the time of submission of a process to the time of completion is termed as a) waiting time b) turnaround time c) response time d) throughput

The number of processes completed per unit time is known as __________. a) Output b) Throughput c) Efficiency d) Capacity

An I/O bound program will typically have : a) a few very short CPU bursts b) many very short I/O bursts c) many very short CPU bursts d) a few very short I/O bursts

Which one of the following is a synchronization tool? a) thread b) pipe c) semaphore d) socket

A parent process calling _____ system call will be suspended until children processes terminate. a) wait b) fork c) exit d) exec

In Unix, Which system call creates the new process? a) fork b) create c) new d) none of the mentioned

A single thread of control allows the process to perform : a) only one task at a time b) multiple tasks at a time c) All of these

Cascading termination refers to termination of all child processes before the parent terminates ______. a) Normally b) Abnormally c) Normally or abnormally d) None of these

If a process fails, most operating system write the error information to a a) log file b) another running process c) new file d) none of the mentioned

The main function of the command interpreter is a) to get and execute the next user-specified command b) to provide the interface between the API and application program c) to handle the files in operating system d) none of the mentioned

The only state transition that is initiated by the user process itself is : a) block b) wakeup c) dispatch d) None of these

The systems which allows only one process execution at a time, are called a) uniprogramming systems b) uniprocessing systems c) unitasking systems d) none of the mentioned

To access the services of operating system, the interface is provided by the a) system calls b) API c) library d) assembly instructions

To enable a process to wait within the monitor, a) a condition variable must be declared as condition b) condition variables must be used as boolean objects c) semaphore must be used d) all of the mentioned

What is a long-term scheduler ? a) It selects which process has to be brought into the ready queue b) It selects which process has to be executed next and allocates CPU c) It selects which process to remove from memory by swapping d) None of these

What is the ready state of a process? a) when process is scheduled to run after some execution b) when process is unable to run until some task has been completed c) when process is using the CPU d) none of the mentioned

When high priority task is indirectly preempted by medium priority task effectively inverting the relative priority of the two tasks, the scenario is called a) priority inversion b) priority removal c) priority exchange d) priority modification

When the process issues an I/O request : a) It is placed in an I/O queue b) It is placed in a waiting queue c) It is placed in the ready queue d) It is placed in the Job queue

Which module gives control of the CPU to the process selected by the short-term scheduler? a) dispatcher b) interrupt c) scheduler d) none of the mentioned

Which of the following state transitions is not possible ? a) blocked to running b) ready to running c) blocked to ready d) running to blocked

Which system call returns the process identifier of a terminated child? a) wait b) exit c) fork d) get

set of processes is deadlock if a) each process is blocked and will remain so forever b) each process is terminated c) all processes are trying to kill each other d) none of the mentioned

When a process terminates : (Choose Two) a) It is removed from all queues b) It is removed from all, but the job queue c) Its process control block is de-allocated d) Its process control block is never de-allocated

In a time-sharing operating system, when the time slot given to a process is completed, the process goes from the running state to the : a) Blocked state b) Ready state c) Suspended state d) Terminated state

Inter process communication : a) allows processes to communicate and synchronize their actions when using the same address space. b) allows processes to communicate and synchronize their actions without using the same address space. c) allows the processes to only synchronize their actions without communication. d) None of these

Scheduling is done so as to : a) increase the turnaround time b) decrease the turnaround time c) keep the turnaround time same d) there is no relation between scheduling and turnaround time

Suppose that a process is in "Blocked" state waiting for some I/O service. When the service is completed, it goes to the : a) Running state b) Ready state c) Suspended state d) Terminated state

The Process Control Block is : a) Process type variable b) Data Structure c) a secondary storage section d) a Block in memory

The Zero Capacity queue : a) is referred to as a message system with buffering b) is referred to as a message system with no buffering c) is referred to as a link d) None of these

The address of the next instruction to be executed by the current process is provided by the a) CPU registers b) program counter c) process stack d) pipe

The child process completes execution,but the parent keeps executing, then the child process is known as : a) Orphan b) Zombie c) Body d) Dead

The processes that are residing in main memory and are ready and waiting to execute are kept on a list called a) job queue b) ready queue c) execution queue d) process queue

Time quantum is defined in a) shortest job scheduling algorithm b) round robin scheduling algorithm c) priority scheduling algorithm d) multilevel queue scheduling algorithm

When several processes access the same data concurrently and the outcome of the execution depends on the particular order in which the access takes place, is called a) dynamic condition b) race condition c) essential condition d) critical condition

Which of the following do not belong to queues for processes ? a) Job Queue b) PCB queue c) Device Queue d) Ready Queue

Which of the following is not the state of a process ? a) New b) Old c) Waiting d) Running e) Ready f) Terminated

Which of the following need not necessarily be saved on a context switch between processes ? (GATE CS 2000) a) General purpose registers b) Translation look-aside buffer c) Program counter d) All of these

Which one of the following can not be scheduled by the kernel? a) kernel level thread b) user level thread c) process d) none of the mentioned

In UNIX, each process is identified by its : a) Process Control Block b) Device Queue c) Process Identifier d) None of these

Mutual exclusion can be provided by the a) mutex locks b) binary semaphores c) both (a) and (b) d) none of the mentioned

Process synchronization can be done on a) hardware level b) software level c) both (a) and (b) d) none of the mentioned

Restricting the child process to a subset of the parent's resources prevents any process from : a) overloading the system by using a lot of secondary storage b) under-loading the system by very less CPU utilization c) overloading the system by creating a lot of sub-processes d) crashing the system by utilizing multiple resources

Scheduling is done so as to : a) increase the waiting time b) keep the waiting time the same c) decrease the waiting time d) None of these

The entry of all the PCBs of the current processes is in : a) Process Register b) Program Counter c) Process Table d) Process Unit

The primary distinction between the short term scheduler and the long term scheduler is : a) The length of their queues b) The type of processes they schedule c) The frequency of their execution d) None of these

The degree of multi-programming is : a) the number of processes executed per unit time b) the number of processes in the ready queue c) the number of processes in the I/O queue d) the number of processes in memory

Turnaround time is : a) the total waiting time for a process to finish execution b) the total time spent in the ready queue c) the total time spent in the running queue d) the total time from the completion till the submission of a process

ith ................ only one process can execute at a time; meanwhile all other process are waiting for the processor. With .............. more than one process can be running simultaneously each on a different processor. a) Multiprocessing, Multiprogramming b) Multiprogramming, Uniprocessing c) Multiprogramming, Multiprocessing d) Uniprogramming, Multiprocessing

In priority scheduling algorithm a) CPU is allocated to the process with highest priority b) CPU is allocated to the process with lowest priority c) equal priority processes can not be scheduled d) none of the mentioned

Message passing system allows processes to : a) communicate with one another without resorting to shared data. b) communicate with one another by resorting to shared data. c) share data d) name the recipient or sender of the message

Scheduling is done so as to : a) increase the throughput b) decrease the throughput c) increase the duration of a specific amount of work d) None of these

Waiting time is : a) the total time in the blocked and waiting queues b) the total time spent in the ready queue c) the total time spent in the running queue d) the total time from the completion till the submission of a process

What is a short-term scheduler ? a) It selects which process has to be brought into the ready queue b) It selects which process has to be executed next and allocates CPU c) It selects which process to remove from memory by swapping d) None of these

What is interprocess communication? a) communication within the process b) communication between two process c) communication between two threads of same process d) none of the mentioned

In the following cases non - preemptive scheduling occurs : (Choose two) a) When a process switches from the running state to the ready state b) When a process goes from the running state to the waiting state c) When a process switches from the waiting state to the ready state d) When a process terminates

In UNIX, the return value for the fork system call is _____ for the child process and _____ for the parent process. a) A Negative integer, Zero b) Zero, A Negative integer c) Zero, A nonzero integer d) A nonzero integer, Zero

In a multi-programming environment : a) the processor executes more than one process at a time b) the programs are developed by more than one person c) more than one process resides in the memory d) a single user can execute many programs at the same time

Messages sent by a process : a) have to be of a fixed size b) have to be a variable size c) can be fixed or variable sized d) None of these

An IPC facility provides atleast two operations : (choose two) a) write message b) delete message c) send message d) receive message

A process stack does not contain a) function parameters b) local variables c) return addresses d) PID of child process

The switching of the CPU from one process or thread to another is called : a) process switch b) task switch c) context switch d) All of these

Which one of the following error will be handle by the operating system? a) power failure b) lack of paper in printer c) connection failure in the network d) all of the mentioned

Which one of the following is not a real time operating system? a) VxWorks b) Windows CE c) RTLinux d) Palm OS

Which of the following are TRUE for direct communication :(choose two) a) A communication link can be associated with N number of process(N = max. number of processes supported by system) b) A communication link can be associated with exactly two processes c) Exactly N/2 links exist between each pair of processes(N = max. number of processes supported by system) d) Exactly one link exists between each pair of processes

By operating system, the resource management can be done via a) time division multiplexing b) space division multiplexing c) both (a) and (b) d) none of the mentioned

Dispatch latency is : a) the speed of dispatching a process from running to the ready state b) the time of dispatching a process from running to ready state and keeping the CPU idle c) the time to stop one process and start running another one d) None of these

If all processes I/O bound, the ready queue will almost always be ______, and the Short term Scheduler will have a ______ to do. a) full,little b) full,lot c) empty,little d) empty,lot

In indirect communication between processes P and Q : a) there is another process R to handle and pass on the messages between P and Q b) there is another machine between the two processes to help communication c) there is a mailbox to help communication between P and Q d) None of these

What is a medium-term scheduler ? a) It selects which process has to be brought into the ready queue b) It selects which process has to be executed next and allocates CPU c) It selects which process to remove from memory by swapping d) None of these

Which of the following does not interrupt a running process ? (GATE CS 2001) a) A device b) Timer c) Scheduler process d) Power failure

Which one of the following is not true? a) kernel is the program that constitutes the central core of the operating system b) kernel is the first part of operating system to load into memory during booting c) kernel is made of various modules which can not be loaded in running operating system d) kernel remains in the memory during the entire computer session

Process are classified into different groups in a) shortest job scheduling algorithm b) round robin scheduling algorithm c) priority scheduling algorithm d) multilevel queue scheduling algorithm

A Process Control Block(PCB) does not contain which of the following : a) Code b) Stack c) Heap d) Data e) Program Counter f) Process State g) I/O status information h) bootstrap program

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