OS MCQ — 9 Practice Questions with Answers

Explanation

Disk scheduling is matched with SCAN because SCAN is a named disk-scheduling algorithm that moves the disk arm back and forth. Batch jobs are commonly served in first-in-first-out order, while round-robin is the standard time-sharing scheduler because it gives each ready process a time quantum. Interrupt handling saves and restores processor context on a stack, so the last saved context is restored first; hence the mapping A-2, B-4, C-1, D-3 makes option C correct.

Explanation

Correct option D is right because after the required I/O service is completed, a blocked process becomes eligible for CPU allocation again and enters the ready state. It does not go directly to the running state; the CPU scheduler must select it first.

Explanation

An orphan process is a child that continues after its parent has terminated; UNIX/POSIX systems reassign such remaining children to a system process. A zombie process is a child that has terminated but has not yet been waited for, so a minimal entry remains in the kernel process table. Both statements match these definitions, so option A is correct.

Explanation

Correct option A is right because multiprogramming depends on selecting one process from the ready queue whenever the CPU becomes available. CPU scheduling is what keeps the processor shared among multiple programs, so it is the basis of a multiprogramming operating system.

Explanation

Correct option D is right because OS X uses a hybrid kernel architecture. It combines ideas associated with microkernels and monolithic kernels, so calling it purely microkernel or purely monolithic is incomplete.