- What is the primary purpose of memory management in an operating system?
A. Allocating CPU time to processes
B. Managing input/output operations
C. Controlling access to hardware resources
D. Managing the use of main memory
Answer: D. Managing the use of main memory
Explanation: The primary goal of memory management is to allocate and deallocate memory resources efficiently, ensuring that processes have the memory they need to execute while preventing conflicts. - What
is the logical address space of a process?
A. The actual physical addresses used by the process
B. The set of addresses generated by the CPU
C. The range of addresses assigned to the process by the operating system
D. The addresses used in input/output operations
Answer: B. The set of addresses generated by the CPU
Explanation: The logical address space refers to the set of addresses generated by the CPU during execution, which are mapped to physical addresses in memory. - What
is the purpose of swapping in memory management?
A. Allocating memory to processes
B. Dynamically adjusting the size of the logical address space
C. Transferring processes between main memory and secondary storage
D. Controlling access to hardware resources
Answer: C. Transferring processes between main memory and secondary storage
Explanation: Swapping is used to move processes between main memory and secondary storage (like disk) to free up space in memory, allowing more processes to execute. - In
contiguous memory allocation, how are processes placed in memory?
A. Processes can be placed anywhere in memory
B. Processes are allocated non-contiguous blocks of memory
C. Processes are allocated consecutive blocks of memory
D. Processes are placed based on priority levels
Answer: C. Processes are allocated consecutive blocks of memory
Explanation: In contiguous memory allocation, processes are assigned consecutive blocks of memory, which can lead to fragmentation issues. - What
is the primary advantage of paging over contiguous memory allocation?
A. Reduced internal fragmentation
B. Simplicity of implementation
C. Improved CPU utilization
D. Efficient use of secondary storage
Answer: A. Reduced internal fragmentation
Explanation: Paging reduces internal fragmentation by dividing memory into fixed-size pages, which helps in more efficient memory utilization compared to contiguous allocation. - In
segmentation, what is a segment?
A. A block of contiguous memory
B. A unit of address space defined by the operating system
C. A unit of time allocated to a process
D. A type of secondary storage
Answer: B. A unit of address space defined by the operating system
Explanation: Segments are variable-sized chunks of memory, such as functions or data arrays, that the operating system uses to allocate memory. - What
is a page fault in the context of demand paging?
A. A page of memory is successfully retrieved from secondary storage
B. A page of memory is not present in main memory and must be brought in
C. A page is swapped out to secondary storage
D. A segment of memory is released by the operating system
Answer: B. A page of memory is not present in main memory and must be brought in
Explanation: A page fault occurs when a page needed by a process is not in main memory and must be fetched from secondary storage. - What
is the purpose of a page replacement algorithm in demand paging?
A. Allocating memory to processes
B. Dynamically adjusting the size of the logical address space
C. Selecting a page to be replaced when a page fault occurs
D. Transferring processes between main memory and secondary storage
Answer: C. Selecting a page to be replaced when a page fault occurs
Explanation: Page replacement algorithms determine which page to remove from memory to make room for a page that has caused a page fault. - What
is internal fragmentation in the context of memory management?
A. Wasted space within a page or segment
B. Fragmentation caused by the allocation of non-contiguous memory
C. The difference between logical and physical address space
D. The space occupied by the operating system in memory
Answer: A. Wasted space within a page or segment
Explanation: Internal fragmentation occurs when allocated memory is larger than needed, leaving unused space within a page or segment. - How
does multi-level paging differ from simple paging?
A. Multi-level paging uses a single level of page tables
B. Simple paging allows for more efficient page replacement
C. Multi-level paging uses multiple levels of page tables
D. Simple paging is not suitable for modern computer architectures
Answer: C. Multi-level paging uses multiple levels of page tables
Explanation: Multi-level paging improves memory management efficiency by breaking down page tables into multiple levels, reducing the amount of memory needed for page tables. - What
is the concept of virtual memory in memory management?
A. Allocating memory to processes
B. Using secondary storage to extend the address space of main memory
C. Dynamically adjusting the size of the logical address space
D. Controlling access to hardware resources
Answer: B. Using secondary storage to extend the address space of main memory
Explanation: Virtual memory allows the system to use disk space as additional memory, extending the apparent size of RAM. - What
is the primary advantage of demand paging over pure paging?
A. Reduced internal fragmentation
B. Simplicity of implementation
C. Improved CPU utilization
D. Efficient use of secondary storage
Answer: C. Improved CPU utilization
Explanation: Demand paging improves CPU utilization by loading pages into memory only when needed, rather than loading all pages at once. - What
is the purpose of overlays in memory management?
A. Dynamically adjusting the size of the logical address space
B. Transferring processes between main memory and secondary storage
C. Allocating memory to processes
D. Swapping portions of a program in and out of main memory
Answer: D. Swapping portions of a program in and out of main memory
Explanation: Overlays allow large programs to be executed in memory by swapping portions of the program in and out of main memory as needed. - How
does segmentation with paging combine the benefits of both segmentation
and paging?
A. By reducing external fragmentation
B. By simplifying the page replacement process
C. By providing protection and flexibility
D. By eliminating the need for secondary storage
Answer: C. By providing protection and flexibility
Explanation: Segmentation with paging combines the flexibility of segmentation (variable-sized segments) with the efficiency of paging (fixed-size pages), allowing better memory protection and management. - What
is the goal of memory protection in an operating system?
A. Maximizing CPU utilization
B. Minimizing response time
C. Preventing unauthorized access and ensuring data integrity
D. Dynamically adjusting the size of the logical address space
Answer: C. Preventing unauthorized access and ensuring data integrity
Explanation: Memory protection ensures that processes cannot access memory areas they should not, preventing data corruption and unauthorized access. - What
is the purpose of a page table in memory management?
A. Controlling access to hardware resources
B. Dynamically adjusting the size of the logical address space
C. Mapping logical addresses to physical addresses
D. Managing input/output operations
Answer: C. Mapping logical addresses to physical addresses
Explanation: A page table is used to translate the logical addresses generated by a process into physical addresses in memory. - How
does the access matrix relate to memory protection in operating systems?
A. It represents the range of access rights assigned to a user
B. It is a visual representation of CPU scheduling
C. It defines access rights for subjects and objects
D. It is used for implementing overlays
Answer: A. It represents the range of access rights assigned to a user
Explanation: The access matrix defines which users (subjects) have access to which objects (e.g., files) and specifies what operations they can perform. - What
is the primary goal of page replacement algorithms in demand paging?
A. Maximizing CPU utilization
B. Minimizing response time
C. Reducing internal fragmentation
D. Efficiently managing the use of secondary storage
Answer: D. Efficiently managing the use of secondary storage
Explanation: Page replacement algorithms are designed to manage memory efficiently by deciding which pages to swap in and out of secondary storage to minimize the performance impact. - How
does segmentation differ from paging in memory management?
A. Segmentation allows for more efficient use of secondary storage
B. Paging provides protection and flexibility, while segmentation does not
C. Segmentation uses a single level of page tables
D. Paging involves dividing the logical address space into fixed-size blocks
Answer: B. Paging provides protection and flexibility, while segmentation does not
Explanation: Paging offers fixed-size blocks of memory, which simplifies protection and management, while segmentation divides memory into variable-sized blocks, which can be more flexible but harder to protect. - What
is a key disadvantage of external fragmentation in memory management?
A. Wasted space within a page or segment
B. Inefficient use of secondary storage
C. Processes waiting indefinitely for resources
D. Unallocated memory scattered throughout the system
Answer: B. Inefficient use of secondary storage
Explanation: External fragmentation occurs when free memory is scattered in small chunks, making it difficult to allocate large blocks of memory efficiently, leading to wasted space in secondary storage.