Bijan Krishna Paul : Operating system examination set 1

To access the services of operating system, the interface is provided by the ___________
a) System calls
b) API
c) Library
d) Assembly instructions

What is the main function of the command interpreter?
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

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 systems which allow only one process execution at a time, are called __________
a) uniprogramming systems
b) uniprocessing systems
c) unitasking systems
d) none 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

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

A 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

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

What is the degree of multiprogramming?
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

10.Which of the following do not belong to queues for processes?

a) Job Queue
b) PCB queue
c) Device Queue
d) Ready Queue

11. 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

12. What is a long-term scheduler?
a) It selects processes which have to be brought into the ready queue
b) It selects processes which have to be executed next and allocates CPU
c) It selects processes which heave to remove from memory by swapping
d) None of the mentioned

13.What is a long-term scheduler?

a) It selects processes which have to be brought into the ready queue
b) It selects processes which have to be executed next and allocates CPU
c) It selects processes which heave to remove from memory by swapping
d) None of the mentioned

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 the mentioned

15.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 the mentioned

16. 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

17.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

18.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

19.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

20. 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

21.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

22.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

23. 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

24. Round robin scheduling falls under the category of ____________

a) Non-preemptive scheduling
b) Preemptive scheduling
c) All of the mentioned
d) None of the mentioned

25 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

26. 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

27. 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

28. A solution to the problem of indefinite blockage of low – priority processes is ____________

a) Starvation
b) Wait queue
c) Ready queue
d) Aging

29. 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

30. 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

31. 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 the mentioned

32. When memory is divided into several fixed sized partitions, each partition may contain ________

a) exactly one process
b) at least one process
c) multiple processes at once
d) none of the mentioned

33. In fixed size partition, the degree of multiprogramming is bounded by ___________

a) the number of partitions
b) the CPU utilization
c) the memory size
d) all of the mentioned

34. 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 the mentioned

35. 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

36. A solution to the problem of external fragmentation is ____________

a) compaction
b) larger memory space
c) smaller memory space
d) none of the mentioned

37. 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 the mentioned

38. 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

39. When the memory allocated to a process is slightly larger than the process, then ____________

a) internal fragmentation occurs
b) external fragmentation occurs
c) both internal and external fragmentation occurs
d) neither internal nor external fragmentation occurs

40. Logical memory is broken into fixed-sized blocks called ________

a) frames
b) pages
c) backing store
d) none of the mentioned

41.Logical memory is broken into blocks of the same size called _________

a) frames
b) pages
c) backing store
d) none of the mentioned

42. Dispatch latency is defined as

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

43. Consider the following statements about process state transitions for a system using preemptive scheduling.(GATE 2020)

I. A running process can move to ready state.

II. A ready process can move to running state.

III. A blocked process can move to running state.

IV. A blocked process can move to ready state.

a) I, II and III only

b) II and III only

c) I, II and IV only

d) I, II, III and IV only

44. Consider a process P running on a CPU. Which one or more of the following events will always trigger a context switch by the OS that results in process P moving to a non-running state (e.g., ready, blocked)? (GATE 2024)

a)P makes a blocking system call to read a block of data from the disk

b)P tries to access a page that is in the swap space, triggering a page fault

c)An interrupt is raised by the disk to deliver data requested by some other process

d) A timer interrupt is raised by the hardware

45. Which of the following process state transitions is/are NOT possible?(GATE 2024)

a)Running to Ready

b)Waiting to Running

c)Ready to Waiting

d) Running to Terminated

46. Suppose a system contains n processes and system uses the round-robin algorithm for CPU scheduling then which data structure is best suited ready queue of the process

a)stack

b)queue

c)circular queue

d)tree

47. Where does the swap space reside ?

a)RAM

b)Disk

c)ROM

d)On-chip cache

48. Which of the following facilitates sharing of codes, data and program modules between processes?

Segments

Page table

Pages

Segment table

49. In which of the following Page replacement Algorithm making pages replacement decisions in such a manner that the total number of page faults during operation of a process is the minimum possible?

LRU Page replacement Algorithm

FIFO page replacement Algorithm

Optimal page replacement algorithm