Operating System CI-321 Practice Final-term Exam

TRUE/FALSE A process can change states from blocked to running.

FALSE

TRUE/FALSE Consider two machines A and B of different architectures, running two different operating systems OS-A and OS-B. Both operating systems are POSIX compliant. The source code of an application that is written to run on machine A must always be rewritten to run on machine B.

FALSE

TRUE/FALSE Deadlock can never occur if a process is allowed to hold a resource while requesting

FALSE

TRUE/FALSE Banker's Algorithm can generate more than one safe sequence.

TRUE

TRUE/FALSE Concurrent execution of threads/processes is achieved using interleaving or overlapping

TRUE

TRUE/FALSE Hybrid Kernel performs better than microkernel OS

TRUE

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

a) a segment number & offset

TRUE/FALSE A context switch can occur only after processing a timer interrupt, but not after any other system call or interrupt.

FALSE

TRUE/FALSE Many consumers can be in CS (critical section) as long as no producers are there.

FALSE

TRUE/FALSE Operating systems typically use only non-preemptive scheduling.

FALSE

TRUE/FALSE Physical address of a process is the address in main memory

FALSE

TRUE/FALSE The need for synchronizing threads that run concurrently and access shared resources only arises if the machine has multiple CPUs.

FALSE

TRUE/FALSE A process in user mode cannot execute certain privileged hardware instructions.

TRUE

TRUE/FALSE An example of an application that could make use of threads is a file server.

TRUE

TRUE/FALSE An operating system can be run within another operating system on its own if it is virtualized using a virtual machine.

TRUE

TRUE/FALSE DMA (Direct Memory Access) is a mechanism for allowing an I/O device to transfer data to and from memory without involving the CPU in the transfer.

TRUE

TRUE/FALSE If a process fails, OS writes the error information in a log file

TRUE

TRUE/FALSE In RR scheduling, the time quantum should be greater with respect to the context-switch time.

TRUE

TRUE/FALSE Number of instructions in a process can be the deciding factor for CPU Scheduling algorithm.

TRUE

TRUE/FALSE The behaviour of a binary semaphore is identical to the behaviour of a Mutex

TRUE

True/False In OS memory management, page sizes are always power of 2.

TRUE

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 the mentioned

a) after a process has made a request to enter its critical section and before the request is granted

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

a) banker's algorithm

__________ is generally faster than _________ and _________ a) first fit, best fit, next fit b) best fit, first fit, next fit c) next fit, best fit, first fit d) none of the mentioned

a) first fit, best fit, next fit

CPU scheduling is the basis of ___________ a) multiprogramming operating systems b) larger memory sized systems c) multiprocessor systems d) none of the mentioned

a) multiprogramming operating systems

When a page fault occurs before an executing instruction is complete if ____________ 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

a) the instruction must be restarted

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) all of the mentioned d) none of the mentioned

a) then the system will not be in a safe state

What are the two steps of a process execution? a) I/O & OS Burst b) CPU & I/O Burst c) Memory & I/O Burst d) OS & Memory Burst

b) CPU & I/O Burst

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

b) Page frame number

An un-interruptible unit is known as ____________ a) single b) atomic c) static d) none of the mentioned

b) atomic

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

b) critical section

With paging there is no ________ fragmentation. a) internal b) external c) either type of d) none of the mentioned

b) external

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 the mentioned

b) is not being used

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

b) race condition

A counting semaphore was initialized to 20. Then 8 P (wait) operations and 5 V (signal) operations were completed on this semaphore. The resulting value of the semaphore is a) 20 b) 8 c) 17 d) 12

c) 17

Multiprogramming systems: a) Are easier to develop than single programming systems b) Execute each job faster c) Execute more jobs in the same time period d) Are used only one large mainframe computers.

c) Execute more jobs in the same time period

Which of the following statement is incorrect I. Windows OS supports GUI II. Unix is a multi-user OS a) Only I b) Only II c) Neither I nor II d) Both I and II

c) Neither I nor II

Which of the following memory management technique gives a User's View to a module of a program in physical memory a) Paging b) Dynamic Partitioning c) Segmentation d) Fixed Partitioning

c) Segmentation

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

c) a technique for overcoming external fragmentation

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) all of the mentioned d) none of the mentioned

c) all of the mentioned

Test And Set instruction is executed ____________ a) after a particular process b) periodically c) atomically d) none of the mentioned

c) atomically

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 the mentioned

c) integer variable

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 cannot be loaded in running operating system d) kernel remains in the memory during the entire computer session

c) kernel is made of various modules which cannot be loaded in running operating system

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

c) logical address

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

c) page

What is Dispatch latency? 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 the mentioned

c) the time to stop one process and start running another one

The data structures available in the Banker's algorithm are ____________ a) Available b) Need c) Spin Waiting d) (a) & (b) e) None of the above

d) (a) & (b)

In Operating Systems, which of the following is/are CPU scheduling algorithms? a) Round Robin b) Shortest Job First c) Priority d) All of the mentioned

d) All of the mentioned