WBJECA 2025 — Computer PYQ

Correct Option: (D) Source code of the program

Explanation

A Process Control Block (PCB) is a data structure used by the operating system to store all the information about a process. It allows the OS to manage process execution, scheduling, and context switching.

• Components of a PCB: A typical PCB contains essential information needed to track a process, including:

  • Process state: (new, ready, running, waiting, etc.)

  • Program counter: The address of the next instruction to be executed.

  • CPU registers: Accumulators, index registers, stack pointers, and general-purpose registers.

  • CPU scheduling information: Priority, pointers to scheduling queues, etc.

• Why (D) is not part of the PCB: The Source code is the high-level language program written by the programmer (e.g., in C or Java). It is stored as a file on the disk. Once compiled and executed, the OS manages the process, but the PCB only holds the control information, not the actual source code. The relationship can be visualized as:

  $$PCB\_Content=\{State,Program\_Counter,Registers,Scheduling\_Info\}$$

  $$Source\_Code\notin PCB\_Content$$