Memory Management MCQs

1. The main disadvantage of paging is:

a) Internal fragmentation b) External fragmentation c) Both a and b d) None of the above

Correct Answer: a) Internal fragmentation

Explanation:
Paging eliminates external fragmentation but may cause internal fragmentation when a process doesn't completely fill its last page frame.

2. Which of the following is true about virtual memory?

a) It is faster than physical memory b) It is larger than physical memory c) It is managed by the compiler d) None of the above

Correct Answer: b) It is larger than physical memory

Explanation:
Virtual memory creates the illusion of a larger memory space by using disk storage to supplement physical RAM.

3. The page fault service time includes:

a) Disk I/O time b) Context switch time c) Both a and b d) None of the above

Correct Answer: c) Both a and b

Explanation:
Page fault handling involves context switching to the OS, disk I/O to fetch the page, and potentially other overhead like updating page tables.

4. The main purpose of the MMU is:

a) To manage CPU scheduling b) To translate logical to physical addresses c) To handle page faults d) None of the above

Correct Answer: b) To translate logical to physical addresses

Explanation:
The Memory Management Unit (MMU) is a hardware component that performs address translation using page tables.

5. Which of the following is not a memory management technique?

a) Paging b) Segmentation c) Deadlock prevention d) None of the above

Correct Answer: c) Deadlock prevention

Explanation:
Deadlock prevention is related to process synchronization, not directly to memory management techniques like paging or segmentation.

6. The main advantage of virtual memory is:

a) Increased CPU speed b) Increased effective memory size c) Reduced disk usage d) None of the above

Correct Answer: b) Increased effective memory size

Explanation:
Virtual memory allows programs to execute as if they have more memory available than physically exists in RAM.

7. The main disadvantage of swapping is:

a) High disk I/O b) High CPU usage c) Increased memory usage d) None of the above

Correct Answer: a) High disk I/O

Explanation:
Swapping entire processes between memory and disk creates significant I/O overhead, slowing down system performance.

8. Which of the following is not a part of the memory hierarchy?

a) Cache b) RAM c) Hard Disk d) None of the above

Correct Answer: d) None of the above

Explanation:
All listed components (cache, RAM, hard disk) are part of the standard memory hierarchy from fastest/smallest to slowest/largest.

9. The main purpose of compaction is to:

a) Reduce internal fragmentation b) Reduce external fragmentation c) Increase memory size d) None of the above

Correct Answer: b) Reduce external fragmentation

Explanation:
Compaction moves allocated memory blocks together to create larger contiguous free blocks, reducing external fragmentation.

10. In segmentation, each segment has:

a) A fixed size b) A variable size c) Both a and b d) None of the above

Correct Answer: b) A variable size

Explanation:
Segments correspond to logical program units (functions, arrays, etc.) and thus naturally have different sizes.

11. The main advantage of multi-level paging is:

a) Reduced page table size b) Increased speed c) Reduced fragmentation d) None of the above

Correct Answer: a) Reduced page table size

Explanation:
Multi-level paging significantly reduces memory usage for page tables by only storing active portions in memory.

12. The main disadvantage of demand paging is:

a) Increased page faults b) Increased memory usage c) Increased disk I/O d) None of the above

Correct Answer: a) Increased page faults

Explanation:
Demand paging can lead to more page faults initially as pages are only loaded when first accessed, though this is offset by memory savings.

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