U.G.C. NET Exam. Dec. 2020-June 2021 Paper II (COMPUTER SCIENCE & APPLICATIONS)

Total Questions: 100

71. Given memory access time as p nanoseconds and additional q nanoseconds for handling the page fault. What is the effective memory access time if a page fault occurs once for every 100 instructions?

Correct Answer: (a)
Solution:

72. In a file allocation system, the following allocation schemes are used:

A. Contiguous
B. Indexed
C. Linked allocation
Which of the allocation scheme(s) given above will not suffer from external fragmentation? Choose the correct answer from the options given below:

Correct Answer: (b) B and C only
Solution:

Contiguous allocation suffer from external fragmentation. But Linked and indexed allocations are non-contiguous, so they will not suffer from external fragmentation.

73. Given below are three statements related to interrupt handling mechanism

A. Interrupt handler routine is not stored at a fixed address in the memory.
B. CPU hardware has a dedicated wire called the interrupt request line used for handling interrupts
C. Interrupt vector contains the memory addresses for speciaized interrupt handlers.
In the context of above statements, choose the correct answer from the options given below:

Correct Answer: (b) Both B and C are TRUE only
Solution:Both B and C are TRUE only

74. Match List-I with List-II

Correct Answer: (b) A ‐ IV , B ‐ III , C ‐ I , D ‐ II
Solution:

Fork () : Fork system call is used for creating a new process, which is called child process, which runs currently with the process that makes the fork() call (pavement process.)
exec() : The exec() family of functions replaces the current process image with a new process image. It loads the program into the current process space and runs it from the entry point. Kill() : kill is a command that is used in several, popular operating systems to send signals to running process.
Exit() : exit() terminates the calling process "immediately"

75. Consider the following 3 processes with the length of the CPU burst time given in milliseconds:

Correct Answer: (c) 4.66
Solution:

Whenever new process arrives, there may be pre-emption of the running process, based on burst time.

76. Read the following and answer the questions: Consider a machine with 16 GB main memory and 32‐bits virtual address space, with page size as 4KB. Frame size and page size is same for the given machine.

The number of bits reserved for the frame offset is ______.

Correct Answer: (a) 12
Solution:

77. Read the following and answer the questions: Consider a machine with 16 GB main memory and 32‐bits virtual address space, with page size as 4KB. Frame size and page size is same for the given machine.

Find number of pages required for the given virtual address space.

Correct Answer: (b)
Solution:

78. Read the following and answer the questions: Consider a machine with 16 GB main memory and 32‐bits virtual address space, with page size as 4KB. Frame size and page size is same for the given machine.

What is the minimum number of bits needed for the physical address?

Correct Answer: (b) 34
Solution:∵ Physical Address space = 16 GB = 2³⁴ ∴ 34 number of bits needed for the physical address.

79. Read the following and answer the questions: Consider a machine with 16 GB main memory and 32‐bits virtual address space, with page size as 4KB. Frame size and page size is same for the given machine.

What is the size of page table for handling the given virtual address space, given that each page table entry is of size 2 bytes?

Correct Answer: (a) 2MB
Solution:

80. Read the following and answer the questions: Consider a machine with 16 GB main memory and 32‐bits virtual address space, with page size as 4KB. Frame size and page size is same for the given machine.

If a process of size 34KB is to be executed on this machine, then what will be the size of internal fragmentation for this process?

Correct Answer: (d) 2 KB
Solution:

2 KB
Page size = 4 KB
= Break process into pages