Operating System Objective Question with Answers | Page-5

41 Spatial locality refers to the problem that once a location is referenced
A it Will referenced again
B it will not be referenced again
C a nearby location will be referenced soon
D none of the above

Answer: Option [C]
42 Page fault occurs when
A the page is in main memory
B the page is not in main memory
C one tries to divide a number by 0
D the page is corrupted by application software

Answer: Option [B]
43 Determine the number of page faults when references to pages in the order - 1, 2, 4, 5, 2, 1, 2, 4. Assume that the main memory can accommodate 3 pages and the main memory already has the pages 1 and 2, with page 1 having been brought earlier than page 2, (Assume LRU algorithm is used)
A 3
B 5
C 4
D none of the above

Answer: Option [C]
44 Which of the following are real-time systems?
A An on-line railway reservation system
B A process control system
C Aircraft control system
D Both (B) and (C)

Answer: Option [D]
45 Necessary conditions for deadlock are
A Non-preemption and circular wait
B Mutual exclusion and partial allocation
C Both (a) and (b)
D None of the above

Answer: Option [C]
46 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 13 P operations and 10 V operations
D Both (B) and (C)

Answer: Option [D]
47 Mutual exclusion problem occurs
A among processes that share resources
B between two disjoint processes that do not interact
C among processes that do not use the same resource
D none of the above

Answer: Option [A]
48 Which of the following.is a service not supported by the operating system?
A I/O operation
B Compilation
C Accounting
D Protection

Answer: Option [B]
49 A state is safe if the system can allocate resources to each process (up to its maximum) in some order and still avoid deadlock. Which of the following are true?
A Deadlocked state is unsafe.
B Deadlocked state is a subset of unsafe state.
C Unsafe state may lead to a deadlock situation.
D All are true.

Answer: Option [D]
50 In which of the following scheduling policies does context switching never take place?
A Round-robin
B Shortest job first
C First-cum-first-served
D Both (B) and (C)

Answer: Option [D]