Consider the following code. #include int main() { int n, i, s = 0; scanf("%d", &n); for (i = 2; i < n; i++) { if (n % i != 0) { continue; } s += i; } printf("%d", s); return 0; } Let the input is a positive integer in the given program. What does the code do?

(A) Calculates the sum of all factors of input integer n (excluding 1 and n).

(B) Calculates the sum of all non-factors of input integer n between 1 and n.

(C) Calculates the sum of all odd value factors of input integer n (excluding 1 and n).

(D) Calculates the sum of all even value factors of input integer n (excluding 1 and n).

January 2025 term · Introduction to C Programming · CS1101

Introduction to C Programming Qualifier: 16 March 2025 (January 2025 term)

The IIT Madras BS Introduction to C Programming (Intro to C Programming) Qualifier paper sat on 16 Mar 2025, in the January 2025 term: 16 questions for 50 marks in 120 minutes. Every question is below with its answer. Take it as a timed mock test to be marked, or read it through first.

Questions: 16
Marks: 50
Duration: 120 min
MCQ: 11
MSQ: 2
Numerical: 3

Take as mock test Practise with answers

Updated 25 Sept 2026

Official paper: IIT M ES QUALIFIER AN EXAM QEQ1 16 Mar 2025 · No negative marking.

Question 1

+2 marksOne correct option

What does the term "ROM" stand for in computer memory architecture?

A
Random Only Module
B
Read Over Memory
C
Random Only Memory
D
Read Only Memory

Show answer

Correct answer

D
Read Only Memory

Question 1 on its own page

Question 2

+2 marksOne correct option

Which of the following is used to terminate a C statement?

A
Period (.)
B
Colon (:)
C
Comma (,)
D
Semicolon (;)

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Correct answer

D
Semicolon (;)

Question 2 on its own pageAlso asked in Qualifier 1 Sept 2024

Question 3

+4 marksOne correct option

Consider the computations given below using the generalized memory model.
1. M[0] ← x
2. M[1] ← y
3. M[2] ← M[0] – M[1]
4. M[1] ← M[2] * M[1]
5. M[0] ← M[2] * M[0]
6. M[2] ← M[0] + M[1]
7. M[3] ← M[2]
What is the value of M[3] at the end of the execution?

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Correct answer

Question 3 on its own page

Question 4

+4 marksOne correct option

The 8-bit binary representation of decimal number -39 in 2's complement notation is __.

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Correct answer

Question 4 on its own page

Question 5

+4 marksOne correct option

Consider the following code.

1#include <stdio.h>
2int main() {
3   int n, i, s = 0;
4   scanf("%d", &n);
5
6   for (i = 2; i < n; i++)
7   {
8      if (n % i != 0)
9      {
10          continue;
11      }
12      s += i;
13   }
14
15   printf("%d", s);
16   return 0;
17 }

Let the input is a positive integer in the given program. What does the code do?

A
Calculates the sum of all factors of input integer n (excluding 1 and n).
B
Calculates the sum of all non-factors of input integer n between 1 and n.
C
Calculates the sum of all odd value factors of input integer n (excluding 1 and n).
D
Calculates the sum of all even value factors of input integer n (excluding 1 and n).

Show answer

Correct answer

A
Calculates the sum of all factors of input integer n (excluding 1 and n).

Question 5 on its own page

Question 6

+3 marksOne correct option

Find the decimal equivalent for the unsigned binary representation (11101110)2.

A
213
B
243
C
233
D
238

Show answer

Correct answer

D
238

Question 6 on its own page

Question 7

+3 marksOne correct option

How many maximum unique characters can be encoded using 7 bits?

A
128 characters
B
127 characters
C
64 characters
D
63 characters

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Correct answer

A
128 characters

Question 7 on its own page

Question 8

+3 marksOne correct option

Consider a decimal number 201. What is the 8 bit binary value of it?

A
1100 1101
B
1101 1001
C
1001 1101
D
1100 1001

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Correct answer

D
1100 1001

Question 8 on its own page

Question 9

+3 marksOne correct option

A
x = 3, y = 4, z = 0
B
x = 3, y = 4, z = 1
C
x = 3, y = 5, z = 0
D
x = 3, y = 5, z = 1

Show answer

Correct answer

B
x = 3, y = 4, z = 1

Question 9 on its own page

Question 10

+3 marksOne correct option

Which of the following is the correct syntax for a switch statement in C?

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Correct answer

Question 10 on its own page

Question 11

+3 marksOne correct option

Consider the below C program.

1#include <stdio.h>
2
3int main() {
4    int a = 10, b = 20;
5    int c = b > a ? b-5 : a+2;
6    printf("%d",c);
7    return 0;
8}

What will be the output of the above program?

A
5
B
10
C
15
D
20

Show answer

Correct answer

C
15

Question 11 on its own page

Question 12

+2 marksOne or more correct options

Which of the following is/are the component(s) of a computer CPU?

Select all that apply.

A
ALU
B
Operating System
C
Registers
D
RAM

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Correct answers

A
ALU
C
Registers

Question 12 on its own page

Question 13

+3 marksOne or more correct options

Which of the following is/are valid identifier(s) in C?

Select all that apply.

A
2nd_var
B
_secondVar
C
Var_2
D
float
E
discount_in_%

Show answer

Correct answers

B
_secondVar
C
Var_2

Question 13 on its own page

Question 14

+4 marksNumerical answer

Consider the below steps of computations.
1. R[0] = 9
2. R[1] = 0
3. R[1] = R[1] + R[0]
4. R[0] = R[0] - 2
5. If R[0] > 0, go to step-3, otherwise go to step-6
6. R[2] = R[1]
What will be the values of R[2] at the end of the computations?

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Correct answer: 25

Question 14 on its own page

Question 15

+4 marksNumerical answer

Consider the following code snippet.

1#include <stdio.h>
2int main() {
3    for (int i = 1; i < 5; i++)
4    {
5        for (int j = 0; j < 6; j++)
6        {
7             printf("Hello C\n");
8        }
9    }
10    return 0;
11 }

How many times will Hello C be printed?

Show answer

Correct answer: 24

Question 15 on its own page

Question 16

+3 marksNumerical answer

Show answer

Correct answer: 20

Question 16 on its own page