[Solution] NET 2021 | The number of bits reserved for the frame offset is

Frame offset is reserved for number of bits

Comprehension:
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 __________?

NTA UGC NET June 2021

Operating System

Memory Management

i➥ 12

ii➥ 24

iii➥ 28

iv➥ 34

Answer: Option I 

Solution:

Given,
Page size = 4KB = 2¹².

Formula used,
Page offset = ⌈log₂⁡(page size)⌉,
Frame offset = Page offset.

Calculation,
Page offset = ⌈log₂⁡(2¹²)⌉
             = ⌈12*log₂2⌉ 
             = ⌈12⌉
             = 12 bits

Note:  log₂2 = 1
Frame offset = Page offset = 12 bits
Therefore, 12 bits is reserved for the frame offset.                         

So, Option(I)is correct.