GATE CS 2021 Set 1 — Question 21

MSQ+1 / -0MediumPaging & Address TranslationMemory ManagementOperating SystemFragmentationMultilevel & Inverted Page Tables

Operating System → Memory Management → Fragmentation

Last updated 5 September 2026

Question

In the context of operating systems, which of the following statements is/are correct with respect to paging?

Correct answer (A) Paging helps solve the issue of external fragmentation.; (C) Paging incurs memory overheads. Solution (A) Correct: Paging allocates memory in fixed-size frames, which eliminates external fragmentation because any free frame can be allocated to a process needing a page. (B) Incorrect: Page size directly impacts internal fragmentation. On average, the last page of a process is half-filled. Larger page sizes lead to more internal fragmentation. (C) Correct: Paging requires data structures like page tables to map logical addresses to physical addresses. These tables consume memory, creating overhead. (D) Incorrect: Multi-level paging is primarily used to reduce the memory size of the page table itself for large address spaces, not necessarily to support pages of different sizes (though some architectures might, it is not the defining necessity). Turn this into a strength. Explore AI-powered practice and doubt support with Success Tracker.

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Correct answer (A) Paging helps solve the issue of external fragmentation.; (C) Paging incurs memory overheads. Solution (A) Correct: Paging allocates memory in fixed-size frames, which eliminates external fragmentation because any free frame can be allocated to a process needing a page. (B) Incorrect: Page size directly impacts internal fragmentation. On average, the last page of a process is half-filled. Larger page sizes lead to more internal fragmentation. (C) Correct: Paging requires data structures like page tables to map logical addresses to physical addresses. These tables consume memory, creating overhead. (D) Incorrect: Multi-level paging is primarily used to reduce the memory size of the page table itself for large address spaces, not necessarily to support pages of different sizes (though some architectures might, it is not the defining necessity).

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