Operating System Questions

1. Define operating system (MU AP-96)
An operating system is a set of program that controls, co-ordinates and supervises the activities of the computer hardware and software.

2. What is the role of an os?

An OS acts as an interface between the user and the computer. It acts as The manager of the resources of the computer.

3. Write the functions of an OS(BU Ap-97)

(i) Memory Management.
(ii) Processor management.
(iii) Interrupt Handling.
(iv) Accounting.
(v) Automatic job sequencing.
(vi) Management and control of I/O devices

4. What is the need for an OS?
A medium is needed to communicate between the user and the m/c. An OS acts as a medium of interface

5. What are the characteristics of an OS(MSU Ap-96)
(i) User friendly .
(ii) Keep track of the status of eaCH RESOURCE.
(iii) Allows sharing of resources(H/W and S/W).
(iv) Provides adequate security.
(v) Protection.

6. What is a process?
A process is basically a program in execution. It is the unit of work in a Modern operating system.


7. What is meant by a process state?
When a process executes, it changes, its status. This is known as process's State.

8. What are the various process states ?

The various process states are
(i) new
(ii) ready
(iii) running
(iv) suspended
(v) terminated

9. How does a process differ from a job?(BDU Ap-96).
A process is an active entity with a program counter specifying the next instructions to execute and a set to associated resources, whereas a batch System executes jobs.(which is a collection of processes).

10. Differentiate program and a process?
A process is a program in execution(ie) A program is a passive entity, Where as a process is an active entity.


11. What is process control Block?
Each process is represented in the operating system by a process control Block(PCB) also called a task control block.

12. What is the function of a process control block?
A (PCB) contains many pieces of information associated with a specific Process. It serves as the repository for any information that may vary From process to process.


13. What are the information contained in a PCB?
A PCB contains pieces of information associated with a specific process, Namely

(i) process state
(ii) program counter
(iii) CPU register
(iv) CPU scheduling information
(v) Memory management information
(vi) Accounting information
(vii) I/O status information

14. What are the operations on process?
(i) create a process
(ii) destroy a process
(iii) suspend a process
(iv) resume a process
(v) change the priority of a process
(vi) block a process
(vii) wakeup a process
(viii) dispatch a process
(ix) enable a process to communicate with another

15. What are the operation involved in creating a process?
(i) name the process
(ii) insert it in the system’s known processes list(or) process table.
(iii) Determine the process’s initial priority
(iv) Create the process control block
(v) Allocate the process’s initial resource.

16. What is the nucleus or kernel of an operating system?

Kernel is the part of the OS which directly makes interface with the Hardware system.

17. What are the main functions of the kernel?

To provide mechanism for
(i) creation and deletion of processes
(ii) inter process communication
(iii) synchronization of processes.

18. What are the components of an OS?
OS which is a collection of programs are of 2 types
(i) control program
(ii) supervisory program


19. What is multi programming?
The ability of keeping several jobs in the memory at one time, where The cpu is switched back and forth among them is called as Multi programming

20. What is the use of Multi Programming ?
Multi programming helps to increase CPU utilization, and to decrease the total time needed to execute the jobs.

21. Illustrate the factors that usually determine the degree of Multi Programming
(MSU: Nov-96)
(i) The number of Programs residing in Primary memory.
(ii) Passing of the control of the CPU rapidly between these programs.
(iii) Protection of user process from one another.

Operating System - I

Multiple Choice Questions in Operating System:

1. Which of the following is an example of a SPOOLED device?
a. The terminal used to enter the input data for a program being executed
b. The secondary memory device in virtual memory system
c. A line printer used to print the output of a number of jobs
d. None of the above

2. concurrent process are :
a. process that do not overlap in time
b. process that overlap in time
c. processes that executed by a processor at the same time
d. none of the above

3. The only state transition that is initiated by the user process itself is
a. Block
b. Dispatch
c. Wakeup
d. None of the above

4. which of the following are real time operating system
a. an on-line railway reservation system
b. a process control system
c. aircraft control system
d. payroll processing system

5. Critical region is
a. A part of the operating system which is not allowed to be accessed by any process
b. A set of instructions that access common shared resource which exclude one another in time
c. The portion of the main memory which can be accessed only by one process at a time
d. None of the above

6. in a time sharing operating system, when the time slot given to a process is completed, the process goes from running state to the
a. BLOCKED state
b. READY state
c. SUSPENDED state
d. TERMINATED state

7. At a particular time, the value of a counting semaphore is 10. It will become 7 after
a. 3 V operations
b. 3 P operations
c. 5 V operations and 2 P operations
d. 13 P operations and 10 V operations

8. Supervisor call
a. is a call made by the supervisor of the system
b. is a call with control function
c. are privileged calls that are used to perform resource management functions, which are controlled by the operating system
d. is a call made by some one working in a root directory

9. Semaphores are used to solve the problem of
a. Race condition
b. Process synchronization
c. Mutual exclusion
d. None of the above

10. At a particular time of computation, the value of a counting semaphore is 7. Then 20 P operations and ‘x’ V operations were completed on this semaphore. If the final value of the semaphore is 5, x will be
a. 15
b. 22
c. 18
d. 13

11. Pre-emptive scheduling is the strategy of the temporarily suspending a running process
a. Before the CPU time slice expires
b. To allow starving process to run
c. When it requests I/O
d. None of the above

12. Mutual exclusion problem occurs between
a. Two disjoint process that do not interact
b. Process that share resources
c. Process that do not use the same resources
d. None of the above

13. Memory protection is no use in a
a. Single user system
b. Non-multiprogramming system
c. Non-multitasking system
d. None of the above

14. Some computer system supports dual mode operation- the user mode and the supervisor or monitor mode. These refers to the modes
a. by which user program handle their data
b. by which the operating system execute user programs
c. in which the processor and the associates hardware operate
d. of memory access

15. Fence register is used for
a. CPU protection
b. Memory protection
c. File protection
d. All of the above

16. Which of the following is a service not supported by the operating system?
a. Protection
b. Accounting
c. Compilation
d. I/O operation

17. In round robin CPU scheduling, as the quantum is increased, the average turn around time
a. increases
b. decreases
c. remains constant
d. varies irregularly

18. In a multiprogramming 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 is resident in the memory
d. a single user can execute many programs in the same time

19. In which of the following scheduling policies does context switching never take place?
a. Round-robin
b. SJF
c. Pre-emptive
d. FCFS

20. 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

21. For implementing a multiprogramming operating system,
a. Special support from processor is essential
b. Special support form is not essential
c. Cache memory must be available
d. More than one processor must be available

22. Distributed system should
a. meet prescribed time constraints
b. aim better resource sharing
c. aim better system utilization
d. aim low system overhead

23. In real time operating system, which of the following is most suitable scheduling scheme?
a. Round-robin
b. FCFS
c. Pre-emptive scheduling
d. Random scheduling

24. Memory protection is normally done by
a. the processor and associated hardware
b. the operating system
c. the compiler
d. the user program

25. Which of the following scheduling algorithms gives minimum average waiting time
a. FCFS
b. SJF
c. Round-Robin
d. Priority

26. Which of the following scheduling policy is well suited for a time sharing operating system
a. SJF
b. Round-robin
c. FCFS
d. Priority

27. Which of the following is well suited for batch processing?
a. Process Control
b. Video game control
c. Preparing pay bills of employees
d. Preparing mailing addresses

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