UGC NET · PAPER 2
UGC NET Paper 2 Computer Science – Unit 5: System Software and Operating System PYQ (December 2022 Shift 1)
Q15. Which RAID level is appropriate for storing the log file of a ticket-booking system where huge database updates are required?
- Level 0
- Level 1
- Level 2
- Level 3
Q17. The model of protection can be viewed as a(n)
- Owner matrix
- Domain matrix
- Access matrix
- Global matrix
Q18. A process in memory also contains a heap section. What is the heap used for?
- Contains temporary data
- Dynamically allocating memory during process run time
- Contains process priority and pointers to scheduling queues
- Contains the amount of CPU and real time used
Q19. How many page faults occur with the optimal algorithm for the reference string 1, 2, 3, 4, 5, 3, 4, 1, 6, 7, 8, 7, 8 with four frames?
- 8
- 7
- 6
- 5
Q20. The degree of concurrency of thread models can be arranged as:
- one-to-one > many-to-one > many-to-many
- one-to-one > many-to-many > many-to-one
- many-to-many > many-to-one > one-to-one
- None of the above
Q51. Which of the following statements are true?
A. If the time quantum is extremely small, round robin can result in a large number of context switches.
B. The average turnaround time of a set of processes does not necessarily improve as the time-quantum size increases.
C. The average turnaround time can be improved if most processes finish their next CPU burst in a single time quantum.
Choose the correct answer from the options given below:
A. If the time quantum is extremely small, round robin can result in a large number of context switches.
B. The average turnaround time of a set of processes does not necessarily improve as the time-quantum size increases.
C. The average turnaround time can be improved if most processes finish their next CPU burst in a single time quantum.
Choose the correct answer from the options given below:
- A only
- A, B only
- B, C only
- A, B, C
Q52. Processes (arrival, execution time in ms): A (0, 6), B (3, 2), C (5, 4), D (7, 6), E (10, 3). Using shortest-remaining-time-first scheduling, the average turnaround time is ____
- 7.2
- 8.2
- 6
- 9
Q53. Select the correct order of basic page replacement:
A. A page-replacement algorithm is used if there is no free frame
B. The process is continued by restarting the instruction that caused the trap
C. The location of the desired page is found on disk
D. The desired page is brought into the newly freed frame and the page and frame tables are updated
A. A page-replacement algorithm is used if there is no free frame
B. The process is continued by restarting the instruction that caused the trap
C. The location of the desired page is found on disk
D. The desired page is brought into the newly freed frame and the page and frame tables are updated
- A, B, D, C
- C, D, A, B
- C, A, D, B
- A, D, B, C
Q70. Match List I (reference bit, modify bit) with List II (enhanced second-chance algorithm)
| List I | List II |
|---|---|
| A. (reference = 0, modify = 0) | I. Must write out before replacement. |
| B. (reference = 0, modify = 1) | II. Probably will be used again soon and needs to be written out. |
| C. (reference = 1, modify = 0) | III. Best page to replace. |
| D. (reference = 1, modify = 1) | IV. Probably will be used again soon. |
- A-II, B-I, C-III, D-IV
- A-II, B-I, C-IV, D-III
- A-III, B-I, C-II, D-IV
- A-III, B-I, C-IV, D-II
Q80. A disk has 300 cylinders (0 to 299). The read-write head is at cylinder 101, moving towards the higher end. Calculate the total head movement with the C-LOOK policy for the requests 123, 45, 197, 87, 250, 198, 280.
- 456
- 450
- 458
- 445
Q86. Statement I: The main objective of using virtual memory is to increase the effective capacity of the memory system.
Statement II: The size of virtual memory can be larger than the main memory.
Statement II: The size of virtual memory can be larger than the main memory.
- Both Statement I and Statement II are true.
- Both Statement I and Statement II are false.
- Statement I is true but Statement II is false.
- Statement I is false but Statement II is true.