Operating system is the one of the most important subject of computer science. Every year a lot of questiones are ased from this subject. In this article we will see some of the questions that were asked in the previous year exams.
1. A graphics card has on board memory of 1 MB. Which of the following modes can the card not support? (GATE CS 2000)
(a) 1600 x 400 resolution with 256 colours on a 17 inch monitor
(b) 1600 x 400 resolution with 16 million colours on a 14 inch monitor
(c) 800 x 400 resolution with 16 million colours on a 17 inch monitor
(d) 800 x 800 resolution with 256 colours on a 14 inch monitor
Answer: (B)
2. Which of the following need not necessarily be saved on a context switch between processes? (GATE CS 2000)
(a) General purpose registers
(b) Translation look-aside buffer
(c) Program counter
(d) All of the above
Answer: (B)
3. Which of the following does not interrupt a running process? (GATE CS 2001)
(a) A device
(b) Timer
(c) Scheduler process
(d) Power failure
Answer: (C)
4. Which of the following scheduling algorithms is non-preemptive? (GATE CS 2002)
a) Round Robin
b) First-In First-Out
c) Multilevel Queue Scheduling
d) Multilevel Queue Scheduling with Feedback
Answer: (B)
5. A file system with 300 GByte uses a file descriptor with 8 direct block address. 1 indirect block address and 1 doubly indirect block address. The size of each disk block is 128 Bytes and the size of each disk block address is 8 Bytes. The maximum possible file size in this file system is
(A) 3 Kbytes
(B) 35 Kbytes
(C) 280 Bytes
(D) Dependent on the size of the disk
Answer (B)
6. Consider the following statements with respect to user-level threads and kernel supported threads
i. context switch is faster with kernel-supported threads
ii. for user-level threads, a system call can block the entire process
iii. Kernel supported threads can be scheduled independently
iv. User level threads are transparent to the kernel
Which of the above statements are true? (GATE CS 2004)
a) (ii), (iii) and (iv) only
b) (ii) and (iii) only
c) (i) and (iii) only
d) (i) and (ii) only
Answer(A)
7. Which of the following is NOT a valid deadlock prevention scheme? (GATE CS 2000)
(a) Release all resources before requesting a new resource
(b) Number the resources uniquely and never request a lower numbered resource than the last one requested.
(c) Never request a resource after releasing any resource
(d) Request and all required resources be allocated before execution.
Answer: (C)
8. The minimum number of page frames that must be allocated to a running process in a virtual memory environment is determined by (GATE CS 2004)
a) the instruction set architecture
b) page size
c) physical memory size
d) number of processes in memory
Answer (A)
9. In a system with 32 bit virtual addresses and 1 KB page size, use of one-level page tables for virtual to physical address translation is not practical because of (GATE CS 2003)
a) the large amount of internal fragmentation
b) the large amount of external fragmentation
c) the large memory overhead in maintaining page tables
d) the large computation overhead in the translation process
Answer (C)
10. Consider a virtual memory system with FIFO page replacement policy. For an arbitrary page access pattern, increasing the number of page frames in main memory will (GATE CS 2001)
a) Always decrease the number of page faults
b) Always increase the number of page faults
c) Some times increase the number of page faults
d) Never affect the number of page faults
Answer: (C)
11. Where does the swap space reside ? (GATE 2001)
(a) RAM
(b) Disk
(c) ROM
(d) On-chip cache
Answer: (B)
12. Which of the following need not necessarily be saved on a context switch between processes? (GATE CS 2000)
(a) General purpose registers
(b) Translation look-aside buffer
(c) Program counter
(d) All of the above
Answer: (B)
13. Which of the following requires a device driver? (GATE CS 2001)
a) Register
b) Cache
c) Main memory
d) Disk
Answer: (D)
