Question 1

Explain the differences between call-by-value and call-by-reference in C. Write separate C programs to swap two numbers using both approaches and analyze the output. Which approach reflects the changes outside the function and why?

Accepted Answer

In C programming, the mechanism by which arguments are passed to functions significantly impacts how data is handled. Two primary methods are call-by-value and call-by-reference, as discussed in Block 2, Unit 5 of MCS-011, which details function parameter passing techniques.

Call-by-value involves passing copies of the actual parameter values from the calling function to the formal parameters of the called function. Any modifications made to these formal parameters within the function do not af

Question 2

Write a C program to calculate the average, highest, and lowest marks obtained by students in a class using an array. Accept n marks from the user and display the results.

Accepted Answer

In MCS-011, arrays are fundamental data structures for storing collections of similar data types, such as marks obtained by students. This program demonstrates how to use an array in C to efficiently store 'n' student marks and then compute their average, the highest mark, and the lowest mark. It exemplifies basic input/output operations, loop constructs, and conditional statements.

First, the program will prompt the user to enter the number of students, 'n'. This value determines the size of t

Question 3

Write a C program to multiply two matrices A and B (of size N×N) and store the result in matrix C. Also, check whether the result is a diagonal matrix.

Accepted Answer

The MCS-011 course introduces fundamental programming concepts using C, including array manipulation and control structures. Matrix operations, such as multiplication, are excellent examples for demonstrating nested loops and multi-dimensional arrays. This program will perform matrix multiplication for two N×N matrices and then verify if the resulting matrix is diagonal, a common application of conditional logic in array processing.

Matrix multiplication of two N×N matrices A and B, resulting

Question 4

Without using built-in string functions, write a menu-driven C program using switch-case to perform the following on two strings:

Accepted Answer

The provided C program is designed as a menu-driven application to perform various operations on two user-input strings, strictly adhering to the constraint of not using built-in string library functions. It employs a `do-while` loop to continuously display a menu of options and a `switch-case` construct to execute the chosen string manipulation task. Before any operations, the program prompts the user to enter two strings, which are safely read using `fgets` to prevent buffer overflows, with tr

Question 5

Explain dynamic memory allocation in C. Write a C program to dynamically allocate memory to store a list of numbers and then compute their sum and standard deviation. Free the memory after use. Discuss memory management in your explanation.

Accepted Answer

Dynamic memory allocation in C allows a program to request and release memory during its execution, rather than at compile time. This is particularly useful when the exact memory requirements, such as the size of an array, are not known beforehand. Unlike static or automatic memory allocation, which uses the stack, dynamic memory allocation utilizes the heap segment of memory.

The primary functions for dynamic memory allocation in C, as covered in MCS-011, are `malloc()`, `calloc()`, `realloc(

Question 6

What is a structure in C? Define a structure for an Employee containing emp_id, name, department, and salary. Write functions to:

Accepted Answer

In C programming, a `structure` (often abbreviated as `struct`) is a user-defined data type that allows you to combine items of different data types under a single name. It is a powerful feature for creating complex data types, enabling the grouping of related pieces of information that logically belong together, such as different attributes of an entity like an employee or a book. Unlike arrays, which store elements of the same data type, structures can hold variables of various types, includin

Question 7

Write a C program that reads student records (roll number, name, and marks) from a file, computes the result (pass/fail), and writes the result into another file with appropriate messages. Discuss the file I/O operations used.

Accepted Answer

The problem requires developing a C program to process student records from an input file, compute their pass/fail status, and then write these results to an output file. This task extensively utilizes C's file input/output (I/O) functionalities, which are a core topic covered in Unit 9: File Handling of the MCS-011 course material. File handling is essential for preserving data beyond a program's execution, enabling persistent storage and retrieval.

First, the program defines a `struct Student

Question 8

What are header files in C? Write a C program that uses a macro to convert Celsius to Fahrenheit and vice versa. Use conditional compilation to enable/disable each conversion. Discuss the significance of preprocessor directives.

Accepted Answer

In C programming, header files are crucial components that contain declarations of functions, macros, and type definitions. They serve as an interface to various libraries or different parts of a larger program, allowing source files to share common declarations without duplicating code. The C preprocessor handles these files using the `#include` directive, effectively copying the content of the header file into the source file before compilation begins. This promotes modularity, code reusabilit

MCS-011 Solved Assignment — January 2026 / July 2025

Problem Solving and Programming | IGNOU Bachelor of Computer Applications (BCA)

MCS-011—January 2026 / July 2025

Problem Solving and Programming

Questions & Answers

Download Study Materials

Related Courses

MCS-011 Assignment Questions — January 2026

QQ1. Explain the differences between call-by-value and call-by-reference in C. Write separate C programs to swap two numbers using both approaches and analyze the output. Which approach reflects the changes outside the function and why?

QQ2. Write a C program to calculate the average, highest, and lowest marks obtained by students in a class using an array. Accept n marks from the user and display the results.

QQ3. Write a C program to multiply two matrices A and B (of size N×N) and store the result in matrix C. Also, check whether the result is a diagonal matrix.

QQ4. Without using built-in string functions, write a menu-driven C program using switch-case to perform the following on two strings:

QQ5. Explain dynamic memory allocation in C. Write a C program to dynamically allocate memory to store a list of numbers and then compute their sum and standard deviation. Free the memory after use. Discuss memory management in your explanation.

QQ6. What is a structure in C? Define a structure for an Employee containing emp_id, name, department, and salary. Write functions to:

QQ7. Write a C program that reads student records (roll number, name, and marks) from a file, computes the result (pass/fail), and writes the result into another file with appropriate messages. Discuss the file I/O operations used.

QQ8. What are header files in C? Write a C program that uses a macro to convert Celsius to Fahrenheit and vice versa. Use conditional compilation to enable/disable each conversion. Discuss the significance of preprocessor directives.