UGC NET · PAPER 2
UGC NET Paper 2 Computer Science – Unit 5: System Software and Operating System PYQ (December 2023)
Q14. An address in main memory is called:
- Virtual address
- Memory address
- Logical address
- Physical address
Q17. The head of a moving-head disk with 200 tracks, numbered 0 to 199, has just finished a request at track 125 and is currently serving a request at track 143. The queue of requests in FIFO order is 86, 147, 91, 177, 94, 150, 102, 175, 130. What will be the total number of head movements required to satisfy these requests with the SCAN algorithm?
- 259 cylinders
- 169 cylinders
- 154 cylinders
- 264 cylinders
Q18. Given 4 GB (≈ 4.3 × 10⁹ bytes) of virtual space, a typical page size of 4 KB and a page-table entry of 5 bytes, how many virtual pages would this imply, and what is the size of the whole page table?
- 1075000 and 5375 KB
- 215000 and 40960 bytes
- 10750 and 10240 bytes
- 43000 and 1024 bytes
Q19. In Linux, where is the user password stored?
- /etc/password
- /root/password
- /etc/passwd
- /root/passwd
Q52. Indexed (grouped) allocation is useful because:
(A) It supports both sequential and direct access.
(B) The entire block is available for data.
(C) It does not require lots of space for keeping pointers.
(D) There is no external fragmentation.
Choose the correct answer from the options given below:
(A) It supports both sequential and direct access.
(B) The entire block is available for data.
(C) It does not require lots of space for keeping pointers.
(D) There is no external fragmentation.
Choose the correct answer from the options given below:
- (A) Only
- (B) and (C) Only
- (B) Only
- (A), (B) and (D) Only
Q53. Which of the following statements are CORRECT?
(A) A process always checks the state of the currently executing process to enter the critical section.
(B) Spin locks use busy waiting.
(C) Periodically testing a variable until some value appears is known as busy waiting.
(D) A critical region is the part of the program where shared memory is accessed.
(E) The printer daemon continuously checks to see if there are any files to be printed.
Choose the correct answer from the options given below:
(A) A process always checks the state of the currently executing process to enter the critical section.
(B) Spin locks use busy waiting.
(C) Periodically testing a variable until some value appears is known as busy waiting.
(D) A critical region is the part of the program where shared memory is accessed.
(E) The printer daemon continuously checks to see if there are any files to be printed.
Choose the correct answer from the options given below:
- (A) and (B) Only
- (B) and (C) Only
- (B) and (D) Only
- (B) and (E) Only
Q70. Match List I with List II
| List I | List II |
|---|---|
| (a) LRU | (I) A page is written to secondary memory only when it has been selected for replacement |
| (b) Demand cleaning | (II) A page that has not been referenced for the longest time is replaced |
| (c) Long-term scheduling | (III) The decision to add to the number of processes that are partially or fully in main memory |
| (d) Medium-term scheduling | (IV) The decision to add to the pool of processes to be executed |
- (a)-(I), (b)-(III), (c)-(IV), (d)-(II)
- (a)-(II), (b)-(I), (c)-(IV), (d)-(III)
- (a)-(III), (b)-(II), (c)-(I), (d)-(IV)
- (a)-(IV), (b)-(II), (c)-(III), (d)-(I)
Q80. Arrange the following levels of interrupt protection within the Linux kernel in order of increasing priority.
(a) User-mode programs
(b) Bottom-half interrupt handlers
(c) Kernel system service routines
(d) Top-half interrupt handlers
Choose the correct answer from the options given below:
(a) User-mode programs
(b) Bottom-half interrupt handlers
(c) Kernel system service routines
(d) Top-half interrupt handlers
Choose the correct answer from the options given below:
- (a), (b), (d), (c)
- (a), (c), (b), (d)
- (a), (c), (d), (b)
- (d), (a), (c), (b)
Q88. Statement (I): A thread is a dispatchable unit of work that does not execute sequentially and is not interruptible.
Statement (II): It is not possible to alter the behaviour of a thread by altering its context when the thread is suspended.
In the light of the above statements, choose the most appropriate answer from the options given below:
Statement (II): It is not possible to alter the behaviour of a thread by altering its context when the thread is suspended.
In the light of the above statements, choose the most appropriate answer from the options given below:
- Both Statement I and Statement II are correct
- Both Statement I and Statement II are incorrect
- Statement I is correct but Statement II is incorrect
- Statement I is incorrect but Statement II is correct