Sunday, August 02, 2009

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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Sunday, July 19, 2009

Overview of Data Communication

1. The ____________ is the physical path over which a message travels.
a. Protocol
b. Medium
c. Signal
d. All the above

2. The information to be communicated in a data communications system is the _________________
a. Medium
b. Protocol
c. Message
d. Transmission

3. Frequency of failure and network recovery time after a failure is measures of the _______________ of a network.
a. Performance
b. Reliability
c. Security
d. Feasibility

4. An unauthorized user is a network ____________ issue.
a. Performance
b. Reliability
c. Security
d. All the above

5. Which topology requires a central controller or hub?
a. Mesh
b. Star
c. Bus
d. Ring

6. Which topology requires a multipoint connection?
a. Mesh
b. Star
c. Bus
d. Ring

7. Communication between a computer and a keyboard involves _______ transmission.
a. Simplex
b. Half-duplex
c. Full-duplex
d. Automatic

8. In a network with 25 computers, which topology would require the most extensive cabling?
a. Mesh
b. Star
c. Bus
d. Ring

9. A television broadcast is an example of ____________ transmission.
a. Simplex
b. Half-duplex
c. Full-duplex
d. Automatic

10. A _____________connection provides a dedicated link between two devices.
a. Point-to-point
b. Multipoint
c. Primary
d. Secondary

11. In a ____________ connection, more than two devices can share a single link.
a. Point-to-point
b. Multipoint
c. Primary
d. Secondary

12. In a transmission, the channel capacity is shared by both communicating devices at all times.
a. Simplex
b. Half-duplex
c. Full-duplex
d. Half-simplex

13. A cable break in a ___________ topology stops all transmission.
a. Mesh
b. Bus
c. Star
d. Primary

14. Which organisation has authority over interstate and international commerce in the communications filed?
a. ITU-T
b. IEEE
c. FCC
d. ISO

15. The Internet model consists of ____________ layers.
a. Three
b. Five
c. Seven
d. Eight

16. The process-to-process delivery of the entire message is the responsibility of the ___________ layer.
a. Network
b. Transport
c. Application
d. Physical

17. The _____________ layer is the layer closest to the transmission medium.
a. Physical
b. Data link
c. Network
d. Transport

18. Mail services are available to network users through the ___________ layer.
a. Data link
b. Physical
c. Transport
d. Application

19. As the data packet moves from the lower to the upper layers, headers are_________
a. Added
b. Subtracted
c. Rearranged
d. Modified

20. As the data packet moves from upper to lower layers, headers are____________
a. Added
b. Removed
c. Rearranged
d. Modified

21. The __________ layer lies between the network layer and the application layer.
a. Physical
b. Data link
c. Transport
d. None of the above

22. Layer 2 lies between the physical and the _______________ layer.
a. Network
b. Data link
c. Transport
d. None of the above

23. When data are transmitted from device A to device B, the header from A’s layer 4 is read by B’s _____________ layer.
a. Physical
b. Transport
c. Application
d. None of the above

24. The _________________ layer changes bits into electromagnetic signals.
a. Physical
b. Data link
c. Transport
d. None of the above

25. The physical layer is concerned with the transmission of ___________ over the physical medium.
a. Programs
b. Dialogs
c. Protocols
d. Bits

26. Which layer functions as a liaison between user support layers and network support layers?
a. Network
b. Physical
c. Transport
d. Application

27. What is the main function of the transport layer?
a. Node-to-node delivery
b. Process-to-process delivery
c. Synchronization
d. Updating and maintenance of routing tables

28. Which of the following is an application layer service?
a. Remote log-in
b. File transfer and access
c. Mail service
d. All the above
_________________________________________________________________________________________________

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