Question : Suppose a 16-bit logical address uses 4 bits for segment number and 12 bits for offset.
Solution :
Correct Answer : 4096 bytes
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Question : Which of the following is a major disadvantage of segmentation?
Solution :
Correct Answer : External fragmentation
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Question : Which information is stored in each entry of the segment table?
Solution :
Correct Answer : Base address and segment limit
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Question : A logical address in segmentation consists of which two components?
Solution :
Correct Answer : Segment number and offset
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Question : Which of the following best describes segmentation in an operating system?
Solution :
Correct Answer : Memory is divided into variable-size logical units called segments
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Question : Consider a demand paging system with:
Page fault rate = 0.02
Memory access time = 100 ns
Page fault service time = 8 ms
What is the Effective Access Time (EAT)?
Solution :
Correct Answer : 160,098 ns
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Question : Which of the following best explains why demand paging improves memory utilization?
Solution :
Correct Answer : Only required pages are loaded into main memory
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Question : Which condition best describes thrashing in a demand paging system?
Solution :
Correct Answer : When page fault rate becomes extremely high and CPU spends most time swapping pages
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Question : Which formula correctly represents the Effective Access Time (EAT) in a demand paging system?
p = page fault rate,
s = page fault service time,
m = memory access time
Solution :
Correct Answer : EAT = p × s + (1 − p) × m
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Question : In a demand paging system, what happens when a process references a page that is not currently in main memory?
Solution :
Correct Answer : The OS generates a page fault and loads the page from secondary memory
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Question : If the physical address space = 64 KB and word size = 8 bytes, what is the number of bits required for the physical address?
Solution :
Correct Answer : 13 bits
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Question : In modern operating systems, which statement about user access to physical addresses is correct?
Solution :
Correct Answer : Users access physical memory indirectly through logical addresses.
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Question : If the physical address space = N words, the number of bits required to represent a physical address is:
Solution :
Correct Answer : Log2 N
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Question : Which statement correctly describes the logical address space?
Solution :
Correct Answer : It is the set of addresses generated by the CPU for a process.
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Question : Which component is primarily responsible for translating logical addresses into physical addresses in an operating system?
Solution :
Correct Answer : Memory Management Unit (MMU)
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Question : When a process tries to access a page that is not currently present in main memory, the event is called:
Solution :
Correct Answer : Page fault
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Question : Which hardware component is primarily responsible for translating logical addresses into physical addresses in a paging system?
Solution :
Correct Answer : Memory Management Unit (MMU)
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Question : Which problem of memory management is significantly reduced by using paging?
Solution :
Correct Answer : External fragmentation
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Question : In paging, logical memory is divided into pages, while physical memory is divided into:
Solution :
Correct Answer : Frames
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Question : Which of the following is the main reason paging is required in an operating system?
Solution :
Correct Answer : To allow non-contiguous allocation of physical memory to processes
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