GATE GATE Operating Systems 2

Question 1

In a demand-paging system, a page fault occurs when:

Accepted Answer

A referenced page is not in physical memory

Answer

A page fault is triggered when a process accesses a virtual page that is not currently loaded into physical memory.

Question 2

What is the purpose of a semaphore in operating systems?

Accepted Answer

To synchronize concurrent processes

Answer

Semaphores are synchronization primitives used to control access to shared resources among concurrent processes.

Question 3

Which of the following is a non-preemptive CPU scheduling algorithm?

Accepted Answer

First Come First Served (FCFS)

Answer

FCFS is non-preemptive because once a process starts executing, it runs to completion without being interrupted.

Question 4

In the context of file systems, what does inode contain?

Accepted Answer

File metadata and pointers to data blocks

Answer

An inode stores file metadata (size, permissions, timestamps) and pointers to the actual data blocks on disk, but not the filename.

Question 5

What is thrashing in the context of virtual memory?

Accepted Answer

Excessive disk I/O due to constant page swapping

Answer

Thrashing occurs when a system spends more time swapping pages in and out of memory than executing actual process instructions.

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