C questions in placement tests and university exams are rarely about syntax alone. Most of what you will find here is output prediction, pointer arithmetic, arrays and strings, structures and unions, storage classes, recursion, and file handling. The explanations walk through memory behaviour step by step, which is usually where the confusion sits rather than in the code itself.
What is the scope of a variable declared inside a function block?
Answer: C
Variables declared inside a block (including function blocks) have block scope and are accessible only within that block.
Q.42Easy
Which of the following is a storage class in C?
Answer: C
The storage classes in C are: auto, register, static, and extern. 'static' is one of them.
Q.43Easy
What is the difference between initialization and assignment in C?
Answer: B
Initialization assigns a value when the variable is declared (int x = 5;). Assignment changes the value later (x = 10;).
Q.44Easy
What is the size of a 'float' data type in C on most 32-bit systems?
Answer: B
On most 32-bit systems, float occupies 4 bytes (32 bits) of memory according to IEEE 754 standard.
Q.45Easy
What is the range of 'signed char' in C?
Answer: B
Signed char uses 8 bits with one bit for sign, giving range -128 to 127 (2^7 to 2^7-1).
Q.46Easy
What happens if you assign a double value to an int variable without casting?
Answer: B
Implicit conversion truncates decimal part. int x = 3.7; results in x=3 with no error.
Q.47Easy
What is the size of the 'char' data type in C on most modern systems?
Answer: A
The 'char' data type occupies 1 byte (8 bits) of memory on virtually all modern C systems, as per the C standard.
Q.48Easy
What is the difference between 'signed' and 'unsigned' char?
Answer: B
Signed char ranges from -128 to 127, while unsigned char ranges from 0 to 255. Both use 1 byte but interpret the bits differently.
Q.49Easy
Which data type would be most appropriate to store a person's age in a program?
Answer: C
Age is an integer value. Using 'int' is appropriate and memory-efficient. Floating-point types are unnecessary for this discrete value.
Q.50Easy
What is the output of: int a = 5, b = 2; printf("%d", a / b);
Answer: B
Both a and b are integers, so integer division is performed: 25 = 2 (remainder discarded).
Q.51Easy
In C programming, which of the following is NOT a fundamental data type?
Answer: C
string is not a fundamental data type in C. Fundamental types are int, float, double, char, and void. Strings are arrays of characters.
Q.52Easy
What is the size of a 'long long int' variable in C on a 64-bit system?
Answer: B
A 'long long int' is guaranteed to be at least 64 bits (8 bytes) by the C99 standard on all systems including 64-bit architectures.
Q.53Easy
Which keyword is used to declare a variable that cannot be modified after initialization?
Answer: C
The 'const' keyword declares a constant variable whose value cannot be modified after initialization. Attempting to modify it results in a compile-time error.
Q.54Easy
Which of the following variable declarations will occupy the LEAST memory?
Answer: C
char data type typically occupies 1 byte, which is the minimum. int is 4 bytes, float is 4 bytes, and double is 8 bytes on most systems.
Q.55Easy
In C programming, when you declare a variable as 'const int x = 5;', what happens if you try to modify it within the program?
Answer: B
The 'const' keyword creates a read-only variable. Once initialized, attempting to modify a const variable results in a compilation error (error: assignment of read-only variable). This is enforced at compile-time, not runtime.
Q.56Easy
What will be the output of the following C code? int x = 5; if (x > 3) printf("A"); else printf("B");
Answer: A
Since x = 5 and 5 > 3 is true, the if block executes and prints 'A'.
Q.57Easy
Which of the following is NOT a valid control flow statement in C?
Answer: B
foreach is not a standard C control flow statement. C has if-else, switch, for, while, do-while, and goto.
Q.58Easy
What is the output of this code? for (int i = 0; i < 3; i++) printf("%d ", i);
Answer: A
The loop runs from i=0 to i=2 (i < 3), printing '0 1 2 '.
Q.59Easy
What is the difference between 'break' and 'continue' in loops?
Answer: A
break terminates the loop entirely, while continue jumps to the next iteration without executing remaining statements.
Q.60Easy
Analyze the ternary operator: int x = (5 > 3) ? 10 : 20; What is the value of x?
Answer: A
Since 5 > 3 is true, the ternary operator returns 10, so x = 10.
