Q1. Memory management is responsible for:

A) CPU scheduling
B) Managing main memory
C) File deletion
D) Disk formatting

Answer: B

Explanation: Memory management handles allocation and deallocation of main memory to processes.

Q2. Logical address is generated by:

A) CPU
B) Hard Disk
C) Compiler only
D) Printer

Answer: A

Explanation: Logical address is generated by the CPU and used by programs during execution.

Q3. Physical address refers to:

A) Virtual memory
B) Actual location in RAM
C) Hard disk location
D) Cache memory only

Answer: B

Explanation: Physical address is the real location of data in main memory (RAM).

Q4. Which converts logical address to physical address?

A) MMU
B) CPU Scheduler
C) Semaphore
D) Compiler

Answer: A

Explanation: MMU (Memory Management Unit) maps logical addresses to physical addresses.

Q5. Contiguous memory allocation means:

A) Memory allocated in continuous blocks
B) Random memory allocation
C) Disk allocation
D) File allocation

Answer: A

Explanation: In contiguous allocation, a process gets one continuous block of memory.

Q6. Fixed partition means:

A) Equal memory partitions created in advance
B) Dynamic partitions
C) No partitions
D) Paging system

Answer: A

Explanation: Fixed partition divides memory into fixed-size blocks before execution.

Q7. Variable partition means:

A) Fixed size blocks
B) Memory blocks of different sizes
C) No allocation
D) Only paging

Answer: B

Explanation: Variable partition creates memory blocks according to process needs.

Q8. Internal fragmentation occurs when:

A) Extra space remains inside allocated block
B) Free space exists outside block
C) CPU becomes idle
D) Disk becomes full

Answer: A

Explanation: Internal fragmentation happens when allocated memory is larger than needed.

Q9. External fragmentation occurs when:

A) Free memory is scattered in small pieces
B) CPU is overloaded
C) Process ends
D) File gets deleted

Answer: A

Explanation: External fragmentation occurs when enough free memory exists but not in one continuous block.

Q10. Compaction is used to reduce:

A) Internal fragmentation
B) External fragmentation
C) CPU utilization
D) Turnaround time

Answer: B

Explanation: Compaction combines small free spaces into one large block to reduce external fragmentation.

Q11. Paging is used to:

A) Eliminate external fragmentation
B) Increase CPU speed
C) Delete files
D) Prevent deadlock

Answer: A

Explanation: Paging divides memory into pages and frames, removing external fragmentation.

Q12. In paging, logical memory is divided into:

A) Frames
B) Pages
C) Blocks
D) Threads

Answer: B

Explanation: Logical memory is divided into pages, while physical memory is divided into frames.

Q13. Physical memory is divided into:

A) Pages
B) Frames
C) Files
D) Segments

Answer: B

Explanation: RAM is divided into equal-size blocks called frames.

Q14. Segmentation divides memory based on:

A) Fixed size
B) Logical units
C) Disk sectors
D) CPU cycles

Answer: B

Explanation: Segmentation divides memory according to logical units like functions, arrays, etc.

Q15. Segment size is:

A) Always fixed
B) Variable
C) Equal to frame size
D) Zero

Answer: B

Explanation: Segment sizes are variable depending on program structure.

Q16. Virtual memory allows:

A) Execution of large programs using small RAM
B) Faster CPU
C) No disk usage
D) No scheduling

Answer: A

Explanation: Virtual memory allows execution of programs larger than physical memory.

Q17. Demand paging means:

A) Load all pages at once
B) Load pages only when needed
C) Delete all pages
D) Use only physical memory

Answer: B

Explanation: In demand paging, pages are loaded into memory only when required.

Q18. Page fault occurs when:

A) Required page is not in memory
B) CPU stops
C) File is deleted
D) Printer fails

Answer: A

Explanation: A page fault happens when a process requests a page not currently in RAM.

Q19. Dirty bit indicates:

A) Modified page
B) Deleted page
C) Free page
D) Empty page

Answer: A

Explanation: Dirty bit shows whether a page has been modified after being loaded into memory.

Q20. Locality of Reference means:

A) Process accesses nearby memory locations
B) Process accesses disk only
C) CPU becomes local
D) No memory access

Answer: A

Explanation: Programs usually access nearby memory locations repeatedly.

Q21. LRU stands for:

A) Last Recently Used
B) Least Recently Used
C) Low Resource Unit
D) Logical Resource Usage

Answer: B

Explanation: LRU replaces the page that has not been used for the longest time.

Q22. FIFO page replacement stands for:

A) First In First Out
B) Fast In Fast Out
C) First Internal First Output
D) File In File Out

Answer: A

Explanation: FIFO removes the oldest loaded page first.

Q23. Optimal page replacement replaces:

A) Oldest page
B) Least recently used page
C) Page that will not be used for longest time
D) Random page

Answer: C

Explanation: Optimal algorithm replaces the page that will not be needed for the longest future time.

Q24. Second Chance algorithm is improvement of:

A) FIFO
B) LRU
C) Optimal
D) Segmentation

Answer: A

Explanation: Second Chance improves FIFO by checking the reference bit before replacement.

Q25. NRU stands for:

A) Not Recently Used
B) New Resource Unit
C) Next Ready Unit
D) No RAM Usage

Answer: A

Explanation: NRU selects pages that have not been used recently.

Q26. Working Set refers to:

A) Set of currently active pages
B) Total hard disk
C) CPU registers
D) All files

Answer: A

Explanation: Working set is the collection of pages actively used by a process.

Q27. Thrashing occurs when:

A) Too many page faults happen
B) CPU becomes fast
C) Files increase
D) Deadlock occurs

Answer: A

Explanation: Thrashing happens when the system spends more time swapping pages than executing processes.

Q28. Protection in memory management is used for:

A) Prevent unauthorized access
B) Increase RAM size
C) Improve disk speed
D) Delete files

Answer: A

Explanation: Memory protection ensures one process cannot access another process’s memory illegally.

Q29. Sharing in memory management means:

A) Multiple processes use same memory safely
B) Delete shared files
C) No protection
D) Faster CPU

Answer: A

Explanation: Sharing allows controlled access to common memory areas.

Q30. Page table is used to:

A) Store page mapping
B) Store files
C) Schedule CPU
D) Detect deadlock

Answer: A

Explanation: Page table keeps the mapping between logical pages and physical frames.