Operating Systems MCQs with Answers | OS Questions – Page 5

Question 81 Operating Systems

A process has finished executing, but its parent has not yet called wait() to collect its exit status. What is the child called?

Correct answer A. Zombie process

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Question 82 Operating Systems

What does the fork() system call return to the child process when it succeeds?

Correct answer A. 0

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Question 83 Operating Systems

Counting the original process, how many processes exist after the C code for (int i = 0; i < 3; i++) fork(); has run?

Correct answer D. 8

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Question 84 Operating Systems

What does a successful call to execve() do to the calling process?

Correct answer C. Replaces the process's program image with a new program while keeping the same process ID

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Question 85 Operating Systems

Which resource do threads of the same process NOT share with each other?

Correct answer C. Their stacks and register sets

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Question 86 Operating Systems

What is a major drawback of user-level threads managed entirely by a library under the many-to-one model?

Correct answer C. If one thread makes a blocking system call, the whole process blocks

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Question 87 Operating Systems

Which multithreading model maps each user thread to its own kernel thread, as Linux and Windows do?

Correct answer D. One-to-one model

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Question 88 Operating Systems

In a batch operating system, how are jobs typically handled?

Correct answer A. Similar jobs are grouped and run one after another without user interaction

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Question 89 Operating Systems

What happens if a user-mode program tries to execute a privileged instruction such as disabling interrupts?

Correct answer C. The hardware traps to the operating system instead of executing it

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Question 90 Operating Systems

What is the purpose of the mode bit provided by CPU hardware?

Correct answer B. It indicates whether the CPU is executing in kernel mode or user mode

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Question 91 Operating Systems

Which statement best describes a distributed operating system?

Correct answer C. It manages a collection of networked computers so that users see them as a single system

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Question 92 Operating Systems

A car’s airbag controller must deploy within a few milliseconds of a crash being detected, every time. Which kind of operating system suits it?

Correct answer C. Hard real-time operating system

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Question 93 Operating Systems

What is the main design goal of a time-sharing operating system?

Correct answer D. Quick response for many interactive users

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