The GATE Grind

GATE 2025 CS (CS1) – Question 14

Operating System · Memory Management and Virtual Memory · 1 mark · Multiple choice

Consider a demand paging memory management system with 32-bit logical address, 20-bit physical address, and page size of 2048 bytes. Assuming that the memory is byte addressable, what is the maximum number of entries in the page table?

  1. $2^{21}$
  2. $2^{20}$
  3. $2^{22}$
  4. $2^{24}$

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: (A) $2^{21}$

Explanation

Page size 2048 = 2^11, so the offset is 11 bits. The page number has 32-11 = 21 bits, so the page table has 2^21 entries.