OSStructuresAndProcesses

Question 1

What is the purpose of an Operating System?

Answer 1

To manage hardware resources and provide an environment for application execution.

Question 2

List three major OS services.

Answer 2

Program execution, I/O operations, and file system management.

Question 3

What is a system call?

Answer 3

An interface between a running program and the operating system.

Question 4

What is the difference between user mode and kernel mode?

Answer 4

User mode limits access to hardware, kernel mode allows full control over the hardware.

Question 5

What is a process?

Answer 5

A program in execution that includes program counter, registers, and variables.

Question 6

What are the five states of a process?

Answer 6

New, Ready, Running, Waiting, Terminated.

Question 7

What information does a Process Control Block (PCB) contain?

Answer 7

Process state, program counter, CPU registers, scheduling information, memory management info, I/O status.

Question 8

What is context switching?

Answer 8

Saving the state of one process and loading the state of another.

Question 9

Difference between program and process?

Answer 9

Program is passive (on disk), process is active (in memory and executing).

Question 10

What is the role of the short-term scheduler?

Answer 10

Selects which process should execute next on the CPU.