C Programming — MCQ Practice Questions & Answers

Question 1

Which of the following is NOT a fundamental data type in C?

Accepted Answer

Correct answer: C. string — C has 5 fundamental data types: int, float, double, char, and void. 'string' is not a fundamental type; it's created using char arrays.

Answer

A. int

Answer

B. float

Answer

D. char

Question 2

What is the size of an 'int' variable in a 32-bit system?

Accepted Answer

Correct answer: B. 4 bytes — In a 32-bit system, an int is typically 4 bytes (32 bits). However, the C standard only guarantees it's at least 2 bytes, so technically it's compiler-dependent. But in practice, 4 bytes is standard.

Answer

A. 2 bytes

Answer

C. 8 bytes

Answer

D. Compiler dependent

Question 3

Which variable declaration is correct in C?

Accepted Answer

Correct answer: C. char _var123; — Variable names must start with a letter or underscore, followed by letters, digits, or underscores. Option C follows this rule correctly.

Answer

A. int 2var;

Answer

B. float var-name;

Answer

D. double var@name;

Question 4

Which keyword is used to declare a variable that cannot be modified?

Accepted Answer

Correct answer: B. const — 'const' keyword makes a variable constant and immutable after initialization.

Answer

A. static

Answer

C. volatile

Answer

D. extern

Question 5

Which of the following is a derived data type in C?

Accepted Answer

Correct answer: B. Array — Derived data types are created from fundamental types. Arrays, pointers, structures, and unions are derived types.

Answer

A. int

Answer

C. char

Answer

D. float

Question 6

How many bits are used to store a 'short int' in a standard C environment?

Accepted Answer

Correct answer: B. 16 bits — Standard C guarantees short int is at least 16 bits (2 bytes). Most systems use exactly 16 bits.

Answer

A. 8 bits

Answer

C. 32 bits

Answer

D. Varies by compiler

Question 7

What is the range of values for a signed char in C?

Accepted Answer

Correct answer: B. -128 to 127 — A signed char occupies 1 byte (8 bits). With sign bit, it ranges from -128 to 127 (2^7 to 2^7-1).

Answer

A. 0 to 255

Answer

C. -256 to 255

Answer

D. -127 to 128

Question 8

Which keyword is used to modify a variable so that it cannot be changed?

Accepted Answer

Correct answer: B. const — The const keyword makes a variable read-only after initialization. Its value cannot be modified during program execution.

Answer

A. static

Answer

C. register

Answer

D. extern

C Programming - MCQ Practice Questions