Process Basics and PCB MCQs: 12 Solved Questions with Explanations

Process, program, PCB, TCB, process table and process stack can sound interchangeable until an option moves one field into the wrong structure. These 12 questions test executable code versus live state, a per-process record versus a per-thread record, address-space contents versus PCB metadata, and saved CPU state versus translation caches. Choose an option before reading its explanation, then name the boundary that makes it correct. For every option, ask whether it describes code, live execution, a PCB, a TCB or the process address space. For a broad set on system calls, dual mode and an introductory context-switch block, start with OS Basics MCQs: 12 Solved (GATE/NET); this set stays with processes and PCB/TCB structure. The TLB question appears in both: there it closes OS structure, while here it tests what PCB-backed execution state excludes. The CS Fundamentals for Exams and Placements category provides the wider sequence.

MCQs 1-2: separate a program from a process

Rule of thumb: A program is passive code stored for execution.

A process is one live execution instance with current CPU state and allocated resources. One program can produce several processes.

Launch editor.bin twice. P17 has PC = 0x00401240; P42 has PC = 0x00408A10. The shared program is passive, but the different counters identify distinct active states.

Question 1

What is a process in the context of an operating system?

• A. A file on disk

• B. A printer connected to the system

• C. A program in execution

• D. The main memory of the computer

Correct answer: C. A program in execution.

A process is executing code together with its current CPU state and allocated resources. A file on disk may hold a program, but it is not executing. Main memory is a resource used by processes rather than a live execution instance. Therefore C is the precise definition.

Question 2

Asked in DSSSB 2018.

A process is a(n) ________ entity, whereas a program is a(n) ________ entity. Options:

• A. Passive, Passive

• B. Passive, Active

• C. Active, Passive

• D. Active, Active

Correct answer: C. Active, Passive.

Stored editor.bin is passive. P17 and P42 are active because execution changes their state. Active does not mean Running: a Ready or blocked process remains live.

MCQs 3-4: choose TCB or PCB from the scope of the state

Use scope. Thread ID, PC, registers and stack pointer belong to a TCB; process-wide management belongs to the PCB. If P17 owns T17.1 and T17.2, the count is 1 PCB + 2 TCBs = 3 records, not three PCBs.

Question 3

Asked in DSSSB 2021, TGT Shift 2.

Data structure maintained by the operating system to maintain information for each thread within a process is known as ______.

• A. Process Control Block

• B. Thread Control Block

• C. Symbol Table

• D. Scheduling Queue

Correct answer: B. Thread Control Block.

“For each thread” decides it. A TCB stores thread ID, PC, registers and stack pointer. A PCB is process-level; a symbol table and a scheduling queue serve other purposes. For thread-private stacks, cancellation, threading models and fork mechanics, continue with Threads and Process Creation MCQs; this set stops at choosing TCB over PCB from the scope of saved state.

Question 4

What does the Process Control Block (PCB) contain?

• A. Only the process ID

• B. Process privileges and state

• C. Process state, program counter, CPU registers, and memory information

• D. CPU temperature information

Correct answer: C. Process state, program counter, CPU registers, and memory information.

C gives the complete set. A process ID alone is too narrow, B omits execution context, and CPU temperature is not per-process state. Saved PC and registers enable exact resumption.

MCQs 5-6: learn what a PCB points to but does not contain

A PCB stores metadata and saved state; code, data, heap and stack remain in the address space. P17's PCB may hold PID = 17, state = Ready, PC = 0x00401240, SP = 0x7FFFEF20, priority 6 and a page-table reference. Its 64 KiB code and 32 KiB data stay outside.

Question 5

Asked in CDAC CCAT 2019.

Process Control Block of a process in an Operating System does not contain:

• A. Process number

• B. Process state

• C. Program counter

• D. Program name

Correct answer: D. Program name.

Process number, state and program counter are standard essential-PCB fields; program name is not. Real kernels may retain a command name in implementation-specific structures, but the textbook answer remains D.

Question 6

Asked in UGC NET 2024, Paper 2 (August).

Which of the following statements are TRUE about Process Control Block (PCB) ?

(A) The PCB contains information about the process state, such as whether it is running, waiting or terminated

(B) The PCB includes the program code and data segments of the process

(C) The PCB stores the process's memory management information, such as page tables and segment tables

(D) The PCB is used to track process scheduling information and CPU registers for process execution

Choose the correct answer from the options given below :

• A. (A), (B) and (C) Only

• B. (B), (C) and (D) Only

• C. (A), (C) and (D) Only

• D. (A) and (B) Only

Correct answer: C. (A), (C) and (D) Only.

A is true because state is metadata. B is false because code and data occupy the address space. C covers memory mappings; D covers scheduling and saved registers. Therefore A+C+D is correct.

MCQs 7-9: process relationships, PID 1 and the process table

An independent process cannot affect or be affected by another. A PID identifies one process; the process table collects current PCBs.

There are three entries, each pointing to or embodying its PCB. PID 319 does not mean 319 current processes.

Question 7

Asked in BEL 2023, Probationary Engineer.

A process is called _____ if it cannot affect, or be affected by, other processes executing in the system.

• A. dependent

• B. independent

• C. co-operating

• D. self-supporting

Correct answer: B. independent.

This defines an independent process. A cooperating process can affect or be affected by another through communication or shared data. The other terms are not the standard pair.

Question 8

Asked in UP Police 2018, Paper 2 Subject Oriented (Shift I).

The PID of the init process is

• A. 0

• B. 1

• C. 3

• D. 4

Correct answer: B. 1.

In the conventional Unix-like model, the first user-space init process is PID 1. PID 0 belongs to kernel or idle machinery. This is not a rule for every operating system.

Question 9

Asked in TCS 2024.

The entry of all the PCBs of the current processes is in __________

• A. Process Register

• B. Program Counter

• C. Process Table

• D. Process Unit

Correct answer: C. Process Table.

The process table organises current records. A program counter is one value inside a PCB, not the collection. The other terms are not its standard name.

MCQs 10-11: process stack and multiprogramming state

Parameters, local variables and return addresses belong to stack frames. A child PID is process-management metadata, not an inherent stack value.

Memory holds P1 at 160 MiB, P2 at 96 MiB, P3 at 224 MiB and P4 at 64 MiB. Count P1, P2, P3, P4: 4 resident processes = degree 4. Two Ready, one Running and one Waiting still total four.

Question 10

Asked in Cognizant 2024.

A process stack does not contain __________

• A. Function parameters

• B. Local variables

• C. Return addresses

• D. PID of child process

Correct answer: D. PID of child process.

Stack frames hold parameters, locals and return addresses. A child PID describes a process relationship. OS structures track it, or an application explicitly stores it; it is not an inherent stack component.

Question 11

Asked in Infosys 2025.

What is the degree of multiprogramming?

• A. the number of processes executed per unit time

• B. the number of processes in the ready queue

• C. the number of processes in the I/O queue

• D. the number of processes in memory

Correct answer: D. the number of processes in memory.

P1 through P4 give degree 4. Completed processes per unit time is throughput; queue lengths count particular states. The earlier Process Management and Process States MCQs owns transition labels, Ready/Running/Blocked paths, schedulers and lifecycle; this set uses degree only to distinguish resident processes from queue counts.

MCQ 12: identify what a context switch saves

P17 is Running with PC = 0x00401240, SP = 0x7FFFEF20, R1 = 37, R2 = 12. PCB42 holds PC = 0x006001A0, SP = 0x7FFFCC80, R1 = 5, R2 = 99. A timer interrupt saves P17, restores P42, then resumes it at 0x006001A0.

A TLB is a translation cache. It may be flushed or distinguished with address-space tags, so it need not be restored like PC, SP and registers. This set uses the switch only to classify PCB-backed saved state; scheduler selection and switch-cost calculations are a separate practice need.

Question 12

Asked in ISRO 2008.

Which of the following need not necessarily be saved on a Context Switch between processes?

• A. General purpose registers

• B. Translation look-aside buffer

• C. Program counter

• D. Stack pointer

Correct answer: B. Translation look-aside buffer.

Registers, PC and SP enable exact resumption. A TLB can be invalidated or tagged instead of saved as process state. “Need not necessarily” makes B architecture-neutral.

Score the set, repair the weak boundary and take the next step

Diagnose misses: Q1-Q2, program versus process; Q3-Q6, PCB, TCB or address space; Q7-Q9, identity and tables; Q10-Q11, stack or multiprogramming; Q12, context-switch state.

Within 24 hours, retry missed questions without options. Redo all 12 after seven days. For guided revision across the full OS sequence, use GATE Guidance by Sanchit Sir.

If process states or thread creation caused the miss, next study the linked material on process states and threads.