CS149_MT#2

4. Run time mapping from virtual to physical address is done by ____________ a) Memory management unit b) CPU c) PCI d) None of the mentioned

a) Memory management unit

2. 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) All of the mentioned

a) TLB miss

10. Which protocol establishes the initial logical connection between a server and a client? a) transmission control protocol b) user datagram protocol c) mount protocol d) datagram congestion control protocol

c) mount protocol

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

c) page

9. If the block of free-space list is free then bit will ____________ a) 1 b) 0 c) any of 0 or 1 d) none of the mentioned

a) 1

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

b) external

4. 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 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

a) The waiting time for process P1 is 3ms

7. What is Scheduling? a) allowing a job to use the processor b) making proper use of processor c) all of the mentioned d) none of the mentioned

a) allowing a job to use the processor

4. Complex scheduling algorithms ____________ a) are very appropriate for very large computers b) use minimal resources c) use many resources d) all of the mentioned

a) are very appropriate for very large computers

3. 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 the mentioned

a) assigning ready processes to CPU

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

a) base address of each page in physical memory

8. In which type of allocation method each file occupy a set of contiguous block on the disk? a) contiguous allocation b) dynamic-storage allocation c) linked allocation d) indexed allocation

a) contiguous allocation

6. What is raw disk? a) disk without file system b) empty disk c) disk lacking logical file system d) disk having file system

a) disk without file system

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

a) each process

1. Physical memory is broken into fixed-sized blocks called ________ a) frames b) pages c) backing store d) none of the mentioned

a) frames

1. Each entry in a translation lookaside buffer (TLB) consists of ____________ a) key b) value c) bit value d) constant

a) key

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

a) logical address

14. For every process there is a __________ a) page table b) copy of page table c) pointer to page table d) all of the mentioned

a) page table

13. 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

a) page table base register

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

a) program counter

8. 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 time sharing 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

a) tQ = 15ms

6. 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

a) the predicted next CPU burst

2. 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

a) using very large time slices converts it into First come First served scheduling algorithm

6. 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

b) Preemptive scheduling

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

b) SJF

1. Which is the most optimal scheduling algorithm? a) FCFS - First come First served b) SJF - Shortest Job First c) RR - Round Robin d) None of the mentioned

b) SJF - Shortest Job First

11. 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

b) Shortened; Lengthened

10. 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

b) Shortest Job First

8. 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) the page table itself d) all of the mentioned

b) a two level paging algorithm

3. 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 the mentioned

b) address space identifier

11. 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 the mentioned

b) becomes more

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

b) cache

5. What is 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

b) first executes the job that came in first in the queue

7. The data structure used for file directory is called ____________ a) mount table b) hash table c) file table d) process table

b) hash table

4. 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 the mentioned

b) hit ratio

2. 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 the mentioned

b) knowing the length of the next CPU request

1. Management of metadata information is done by ____________ a) file-organisation module b) logical file system c) basic file system d) application programs

b) logical file system

4. To create a new file application program calls ____________ a) basic file system b) logical file system c) file-organisation module d) none of the mentioned

b) logical file system

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

b) multiprogramming systems

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

b) page number

3. Every address generated by the CPU is divided into two parts. They are ____________ a) frame bit & page number b) page number & page offset c) page offset & frame bit d) frame offset & page offset

b) page number & page offset

6. 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

b) page table base register

1. Physical memory is broken into fixed-sized blocks called ________ a) frames b) pages c) backing store d) none of the mentioned

b) pages

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

b) pages

5. 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

b) paging

6. The size of a page is typically ____________ a) varied b) power of 2 c) power of 4 d) none of the mentioned

b) power of 2

5. What will happens when a process closes the file? a) per-process table entry is not removed b) system wide entry's open count is decremented c) all of the mentioned d) none of the mentioned

b) system wide entry's open count is decremented

12. 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 the mentioned

b) very high speed logic

9. 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

c) 68.5 ns

9. 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

10. Paging increases the ______ time. a) waiting b) execution c) context - switch d) all of the mentioned

c) context - switch

9. 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

c) first come, first served

9. 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

c) frame

6. 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

c) is in the process's logical address space

7. Choose one of the disadvantages of the priority scheduling algorithm? 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 the mentioned

c) it can lead to some low priority process waiting indefinitely for the CPU

3. 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

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

c) valid - invalid

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

d) Aging

12. 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

d) I, II and III Explanation: I) Shortest remaining time first scheduling is a preemptive version of shortest job scheduling. It may cause starvation as shorter processes may keep coming and a long CPU burst process never gets CPU.II) Preemption may cause starvation. If priority based scheduling with preemption is used, then a low priority process may never get CPU.III) Round Robin Scheduling improves response time as all processes get CPU after a specified time.

5. 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

d) SRTN scheduling - Shortest Remaining Time Next

2. A file control block contains the information about ____________ a) file ownership b) file permissions c) location of file contents d) all of the mentioned

d) all of the mentioned

3. Which table contains the information about each mounted volume? a) mount table b) system-wide open-file table c) per-process open-file table d) all of the mentioned

d) all of the mentioned

10. 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

d) i, ii and iii

8. What is 'Aging'? 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

d) increasing the priority of jobs to ensure termination in a finite time

7. 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

d) m - n, n

5. 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

d) protection bit with each page

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

d) registers

15. 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

d) slowed by a factor of 2

10. 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

d) user programs can implement dynamic loading without any special support from hardware or operating system