Operating System Objective Question with Answers | Page-2

11 Virtual memory is
A an extremely large main memory
B an extremely large secondary memory
C a type of memory used in super computers
D an illusion of an extremely large memory

Answer: Option [D]
12 Overlay is
A a specific memory location
B a part of an operating system
C overloading the system with many user files
D a single contiguous memory that was used in the olden days for running large programs by swapping.

Answer: Option [D]
13 The only state transition that is initiated by the user process itself is
A block
B wakeup
C dispatch
D none of the above

Answer: Option [A]
14 Kernel is
A the software which monitors the operating system
B the set of primitive functions upon which the rest of operating system functions are built up
C considered as the critical part of the operating system
D none of the above

Answer: Option [B]
15 Sector interleaving in disks is done by
A the operating system
B the disk manufacturer
C the disk controller cord
D none of the above

Answer: Option [A]
16 Dirty bit is used to show the
A wrong page in the memory
B page with corrupted data
C page that is less frequently accessed
D page that is modified after being loaded into cache memory

Answer: Option [D]
17 The first-fit, and the worst-fit algorithm can be used for
A linked allocation of memory
B indexed allocation of memory
C contiguous allocation of memory
D all of the above

Answer: Option [C]
18 In a paged memory, the page hit ratio is 0.35. The time required to access a page in secondary memory is equal to 100 ns. The time required to access a page in primary memory is 10 ns. The average time required to access a page is
A 3.0 ns
B 68.0 ns
C 68.5 ns
D 78.5 ns

Answer: Option [C]
19 In a multi-user operating system, 20 requests are made to use a particular resource per hour on an average. The probability that no requests are made in 45 minutes is
A e-15
B e-5
C 1 - e-5
D 1 – e-10

Answer: Option [D]
20 Disk scheduling involves deciding
A which disk should be accessed next
B the order in which disk access requests must be serviced
C the physical location where files should be accessed in the disk
D none of the above

Answer: Option [B]