Memory Allocation and Paging: A Comprehensive Guide for Operating Systems

Question 1

Which of the following is NOT considered an advantage of virtual memory?

Accepted Answer

Reduced program execution time

Answer

Extended memory capacity

Answer

Improved multitasking capabilities

Answer

Elimination of memory fragmentation

Question 2

What is the term used to describe a page that has been removed from main memory but still resides on the disk?

Accepted Answer

Non-resident page

Answer

Resident page

Answer

Orphan page

Answer

Zombie page

Question 3

Which memory management technique enables multiple programs to share the same physical memory space simultaneously?

Accepted Answer

Virtual memory

Answer

Segmentation

Answer

Paging

Answer

Demand paging

Question 4

Explain the difference between internal and external fragmentation in memory management.

Accepted Answer

Internal fragmentation occurs when allocated memory is not fully utilized, while external fragmentation occurs when memory is divided into small unusable portions.

Answer

External fragmentation occurs when allocated memory is not fully utilized, while internal fragmentation occurs when memory is divided into small unusable portions.

Answer

Internal and external fragmentation are essentially the same concept.

Answer

Neither internal nor external fragmentation can occur in a well-managed memory system.

Question 5

Which of the following is NOT a potential benefit of implementing a paging system?

Accepted Answer

Reduced system overhead

Answer

Improved isolation of processes

Answer

Increased memory utilization

Answer

Enhanced performance

Question 6

Name the algorithm commonly used to select a page for replacement when a new page needs to be loaded into memory.

Accepted Answer

Least Recently Used

Answer

Most Recently Used

Answer

First-In First-Out

Answer

Least Frequently Used

Question 7

In the Buddy system, memory is divided into blocks of which of the following sizes?

Accepted Answer

Powers of two

Answer

Multiples of four

Answer

Arbitirary sizes

Answer

Fixed sizes

Question 8

The main advantage of using paging in memory management is that it

Accepted Answer

Reduces memory fragmentation

Answer

Increases processor speed

Answer

Eliminates the need for a memory manager

Answer

Improves data security

Question 9

A potential disadvantage of using virtual memory is

Accepted Answer

Increased system overhead

Answer

Reduced memory access time

Answer

Enhanced memory capacity

Answer

Improved multitasking

Question 10

Demand paging differs from prepaging in that

Accepted Answer

Demand paging loads pages into memory only when needed, while prepaging loads pages into memory in advance.

Answer

Prepaging loads pages into memory only when needed, while demand paging loads pages into memory in advance.

Answer

Demand paging and prepaging are the same techniques and do not differ.

Answer

Demand paging is used for user-level processes, while prepaging is used for kernel-level processes.

Question 11

A translation lookaside buffer (TLB) in memory management

Accepted Answer

Stores recently used virtual-to-physical address translations

Answer

Manages the allocation and deallocation of memory pages

Answer

Handles page faults

Answer

Protects memory from unauthorized access

Question 12

The main function of a memory management unit (MMU) is to

Accepted Answer

Translate virtual addresses into physical addresses

Answer

Manage the allocation and deallocation of memory

Answer

Protect memory from unauthorized access

Answer

Handle page faults

Question 13

In contiguous memory allocation, how are memory addresses assigned to processes?

Accepted Answer

Contiguously, with no gaps between addresses

Answer

Dispersedly, with gaps between addresses

Answer

Randomly, tanpa any discernible pattern

Answer

Based on process priority

Question 14

What is the primary function of the Memory Management Unit (MMU)?

Accepted Answer

To translate virtual addresses into physical addresses

Answer

To keep track of free and allocated memory

Answer

To provide isolation between processes

Answer

To manage cache and paging

Question 15

In paging, what is the logical address space divided into?

Accepted Answer

Pages

Answer

Segments

Answer

Blocks

Answer

Frames

Question 16

Which page replacement algorithm is commonly used to determine which page should be replaced in a system with virtual memory?

Accepted Answer

Least Recently Used (LRU)

Answer

First Come First Served (FCFS)

Answer

Most Recently Used (MRU)

Answer

Optimal Page Replacement

Question 17

What is a key advantage of using virtual memory?

Accepted Answer

It extends the capacity of the physical memory

Answer

It enhances process isolation

Answer

It eliminates memory fragmentation

Answer

It boosts system performance

Question 18

What is the fundamental difference between demand paging and prepaging?

Accepted Answer

Demand paging brings pages into memory only when needed, whereas prepaging brings all pages into memory before execution.

Answer

Prepaging brings pages into memory only when needed, whereas demand paging brings all pages into memory before execution.

Answer

Demand paging is used in virtual memory systems, while prepaging is used in physical memory systems.

Answer

Prepaging is more efficient than demand paging.

Question 19

Which of the following is a potential drawback of non-contiguous memory allocation?

Accepted Answer

Increased memory fragmentation

Answer

Reduced system performance

Answer

Enhanced process isolation

Answer

Less complex memory management

Question 20

What is the primary purpose of a page fault?

Accepted Answer

To retrieve a page from secondary storage into main memory

Answer

To allocate a new page to a process

Answer

To deallocate a page from a process

Answer

To update the page table

Question 21

Which of the following is a limitation of virtual memory?

Accepted Answer

Potential for page faults

Answer

Increased memory capacity

Answer

Improved performance

Answer

Reduced memory fragmentation

Question 22

What is the key difference between physical memory and virtual memory?

Accepted Answer

Virtual memory can exceed the size of physical memory.

Answer

Physical memory is tangible, whereas virtual memory is conceptual.

Answer

Physical memory is used by the operating system, while virtual memory is used by applications.

Answer

Physical memory is faster than virtual memory.

Question 23

What is the function of a page table in virtual memory management?

Accepted Answer

To map virtual addresses to physical addresses

Answer

To manage the allocation and deallocation of pages

Answer

To handle page faults

Answer

To store the contents of pages

Question 24

Identify the drawback associated with virtual memory:

Accepted Answer

Slower performance compared to physical memory

Answer

Increased memory overhead

Answer

Reduced reliability

Answer

Increased security risks

Question 25

What is the primary objective of a Translation Lookaside Buffer (TLB)?

Accepted Answer

Accelerate memory access by storing recently used page table entries

Answer

Minimize the frequency of page faults

Answer

Handle virtual memory page translations

Answer

Manage the allocation of physical memory

Question 26

Which option is NOT a goal of memory management?

Accepted Answer

Enhancing system reliability

Answer

Optimizing memory utilization

Answer

Minimizing memory fragmentation

Answer

Providing efficient data access

Question 27

What term describes the algorithm employed to select a page for replacement during a page fault?

Accepted Answer

Page replacement policy

Answer

Paging algorithm

Answer

Swapping policy

Answer

Virtualization technique

Question 28

Explain the fundamental distinction between contiguous and non-contiguous memory allocation:

Accepted Answer

Contiguous allocation assigns data in sequential memory locations, while non-contiguous allocation does not

Answer

Non-contiguous allocation is more efficient than contiguous allocation

Answer

Contiguous allocation is limited to programs with small memory requirements

Answer

Non-contiguous allocation is incompatible with contemporary operating systems

Question 29

Which of the following is an advantage of contiguous memory allocation?

Accepted Answer

Improved data locality and cache performance

Answer

Faster memory access speeds

Answer

Reduced memory fragmentation

Answer

Increased multitasking efficiency

Question 30

What is the purpose of a page table in virtual memory management?

Accepted Answer

To map virtual memory addresses to physical memory locations, enabling processes to access more memory than physically available.

Answer

To store the contents of modified pages until they can be written back to disk.

Answer

To manage page faults and ensure smooth memory access despite physical memory limitations.

Answer

To prevent memory leakage by keeping track of allocated and deallocated memory blocks.

Question 31

Which of the following factors does NOT affect the efficiency of paging?

Accepted Answer

Number of I/O devices: The number of I/O devices does not directly impact paging efficiency.

Answer

Page size: Larger page sizes can reduce TLB misses but increase internal fragmentation.

Answer

Translation lookaside buffer (TLB) size: A larger TLB can cache more page table entries, reducing page faults.

Answer

Memory access speed: Faster memory can reduce the overhead of page faults.

Question 32

What is the primary purpose of a translation lookaside buffer (TLB)?

Accepted Answer

To cache frequently accessed page table entries, reducing the number of memory accesses required to translate virtual addresses.

Answer

To translate virtual memory addresses to physical memory locations.

Answer

To manage page faults and handle memory protection violations.

Answer

To store the contents of modified pages until they can be written back to physical memory.

Question 33

When memory demand is high, how does demand paging impact system performance?

Accepted Answer

It severely degrades system performance due to excessive page faults and thrashing.

Answer

It significantly enhances system performance.

Answer

It has a minor impact on system performance.

Answer

It eliminates the requirement for contiguous memory allocation, resulting in improved performance.

Question 34

How does demand paging, in conjunction with the principle of locality of reference, enhance system performance?

Accepted Answer

It leverages the tendency of programs to access data locally, reducing page faults.

Answer

It eliminates the need for contiguous memory allocation, minimizing fragmentation.

Answer

It prevents thrashing by ensuring all pages are always in memory.

Answer

It reduces the size of the page table, optimizing memory usage.

Question 35

Describe the structure of a page table and explain how it facilitates the translation of virtual memory addresses to physical memory addresses.

Accepted Answer

A page table is a hierarchical data structure that maps virtual memory addresses to their corresponding physical memory addresses.

Answer

A page table is a static data structure that is created at system boot and remains unchanged.

Answer

A page table stores the physical addresses of all pages belonging to a process.

Answer

Page tables are not necessary for virtual memory management.

Question 36

What is the primary function of a page table in a computer operating system?

Accepted Answer

To translate virtual memory addresses to their corresponding physical memory addresses

Answer

To store the contents of the physical memory pages

Answer

To manage page faults and handle page replacement

Question 37

In the context of paging, what is the term used to describe a page that has been temporarily moved to a secondary storage device like a hard disk?

Accepted Answer

Paged out

Answer

Page hit

Answer

Paged in

Answer

Page fault

Question 38

Which technique listed below is NOT commonly utilized to reduce the occurrence of page faults?

Accepted Answer

Buddy allocation

Answer

Demand paging

Answer

Multi-level page tables

Answer

Prefetching

Question 39

Explain the fundamental difference between virtual memory and physical memory.

Accepted Answer

Virtual memory represents a larger, abstract address space managed by the operating system, while physical memory refers to the actual physical hardware memory installed in the computer.

Answer

Virtual memory is always faster than physical memory

Question 40

What is one of the key benefits of employing a hierarchical page table structure in a computer system?

Accepted Answer

Reduced memory overhead compared to a flat page table structure

Answer

Increased page fault time

Answer

Increased memory fragmentation

Answer

Reduced cache efficiency

Question 41

What is the primary purpose of a translation lookaside buffer (TLB) in the context of paging?

Accepted Answer

To cache recently used page table entries, providing faster access to frequently accessed memory locations

Answer

To store the entire page table, eliminating the need for memory lookups

Answer

To perform page replacement algorithms and determine which pages to evict from memory

Question 42

Identify a disadvantage associated with non-contiguous memory allocation.

Accepted Answer

Increased fragmentation, leading to inefficient memory utilization

Answer

Faster memory access

Answer

Simplified memory management

Answer

Reduced memory overhead

Question 43

Which memory allocation technique assigns a continuous block of memory to a running process, without fragmentation?

Accepted Answer

Contiguous allocation

Answer

Segmentation

Answer

Virtual memory

Answer

Paging

Question 44

Identify one of the primary advantages of paging over segmentation in memory management.

Accepted Answer

Elimination of external fragmentation, optimizing memory usage and reducing wasted space

Answer

Improved process isolation

Answer

Reduced memory overhead

Answer

Simplified memory management

Question 45

When a page fault occurs in a computer system, what is the typical action taken by the operating system?

Accepted Answer

The operating system loads the missing page from secondary storage (e.g., hard disk) into main memory

Answer

The operating system swaps out another page from memory to make space

Answer

The operating system ignores the page fault and continues execution

Answer

The operating system terminates the process that caused the page fault

Question 46

Which of the following is NOT a factor that affects page size?

Accepted Answer

CPU speed

Answer

Process size

Answer

Disk speed

Answer

Memory size

Question 47

Virtual memory is a technique that:

Accepted Answer

Extends the size of the physical memory

Answer

Eliminates memory fragmentation

Answer

Reduces page faults

Answer

Improves process isolation

Question 48

In a demand paging system:

Accepted Answer

Pages are only loaded into memory when they are needed

Answer

All pages are loaded into memory at once

Answer

Pages are loaded into memory in advance

Question 49

What is the primary advantage of paging over contiguous memory allocation?

Accepted Answer

Reduced external fragmentation

Answer

Simpler memory management algorithms

Answer

Lower memory overhead

Answer

Faster memory access times

Question 50

In a paging system with a page size of 4KB, what is the frame number for a logical address 0x00005A3C?

Accepted Answer

0x000D

Answer

0xA3C0

Answer

0x0005

Answer

0x5A3C

Question 51

Which of the following is NOT a component of a typical page table entry?

Accepted Answer

Process ID

Answer

Frame number

Answer

Present/absent bit

Question 52

What is the role of the Translation Lookaside Buffer (TLB)?

Accepted Answer

To speed up address translation by caching recently used page table entries

Answer

To store the entire page table for faster access

Answer

To manage the allocation and deallocation of frames in physical memory

Question 53

What happens during a page fault?

Accepted Answer

The operating system loads the required page from secondary storage into main memory

Answer

The CPU switches to a different process while the current one waits

Answer

The program terminates due to an illegal memory access attempt

Question 54

Which of the following is a benefit of using virtual memory?

Accepted Answer

Allows programs larger than physical memory to run

Answer

Eliminates the possibility of fragmentation

Answer

Increases the speed of memory access

Answer

Reduces the need for memory management

Question 55

What is the difference between internal and external fragmentation?

Accepted Answer

Internal fragmentation occurs within a page or segment, while external fragmentation occurs between allocated memory blocks

Answer

Internal fragmentation is caused by variable-sized partitions, while external fragmentation is caused by fixed-sized partitions

Question 56

In a system using segmentation, what does each segment represent?

Accepted Answer

A logical unit of a program, such as code, data, or stack

Answer

A page within a virtual address space

Answer

A fixed-size block of physical memory

Question 57

What is the purpose of the 'dirty bit' in a page table entry?

Accepted Answer

It indicates whether the page has been modified since it was loaded into main memory

Answer

It tracks the number of times the page has been accessed by the process

Answer

It signals if the page is currently present in main memory or needs to be fetched