Computer Science Grade 10 Send-Ups Exam 2024 FIC Kohat

Answer Key for SECTION-B (Marks 22)

Q.2 Short Questions……….

i. Define Algorithm. Also describe its role.

Definition of Algorithm
An algorithm is a step-by-step procedure or set of rules to solve a specific problem or perform a
task.

Role of an Algorithm

• Serves as a blueprint for solving problems systematically.

• Ensures tasks are completed efficiently, consistently, and logically.

Alternative Answer
Candid Solutions: A programmer identifies solutions by analyzing the problem requirements,
testing different logic paths, and considering edge cases to ensure robustness.

ii. Why is it important to terminate a statement with a semicolon in C language?

Importance

• In C, the semicolon marks the end of a statement, allowing the compiler to identify
statement boundaries.

What Happens if Omitted?

• Compilation errors occur because the compiler cannot parse the code correctly.

Alternative Answer
Two Commonly Used Format Specifiers in C:

1. %d - Used for integers (e.g., printf("%d", num);).

2. %f - Used for floating-point numbers (e.g., printf("%f", value);).

iii. Write two characteristics of high-level languages.

By: Waseem Khan FIC Kohat

Characteristics

1. User-friendly: High-level languages use syntax closer to human language, making them
easier to understand and write.
2. Portability: High-level programs can run on multiple platforms with minimal or no
modifications.

Alternative Answer
Why Java is Ideal for Network Computing:

• Platform Independence: Java programs run on any device with a JVM.

• Built-in Libraries: Java provides networking APIs like java.net for seamless
communication.

iv. Explain the use of conditional operators with an example.

Use of Conditional Operators

• Conditional operators (? :) simplify decision-making by evaluating a condition and

choosing between two expressions.

Example

int a = 10, b = 20, max;

max = (a > b) ? a : b; // Assigns max to the larger value.

printf("Maximum: %d", max);

Alternative Answer

C Program with if Statement:

#include <stdio.h>
int main()
{
int num = 10;
if (num > 5)
{
printf("Number is greater than 5");
}
return 0;
By: Waseem Khan FIC Kohat
}

v. Write a C program that prints numbers from 1 to 10 using a For loop.

Program:

#include <stdio.h>
int main()
{
for (int i = 1; i <= 10; i++)
{
printf("%d ", i);
}
return 0;
}

Alternative Answer

Print Uppercase Letters Using While Loop:

#include <stdio.h>

int main()

{
int ascii = 65; // ASCII value of 'A'
while (ascii <= 90)
{
printf("%c", ascii);
ascii++;
}
return 0;
}

vi. Differentiate between compiler and interpreter.

Compiler Interpreter
Translates entire code into machine
Translates and executes code line-by-line.
code.
Slower as translation and execution happen
Faster execution after compilation.
simultaneously.
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Alternative Answer

Evaluate Expressions:

1. 9+6×(5+3)=579 + 6 \times (5 + 3) = 57

2. 120/15/5=1.6120 / 15 / 5 = 1.6

vii. Algorithm to Find Interest on a Given Amount

Algorithm:

1. Start.
2. Input principal, rate, time.
3. Calculate interest: Interest=Principal×Rate×Time/100\text{Interest} = \text{Principal}
\times \text{Rate} \times \text{Time} / 100.
4. Output the interest.
5. End.

Alternative Answer

Flowchart for Even Numbers (50 to 100):

• Start → Set num = 50 → Check num <= 100 → Print num if even → Increment
num → Repeat → End.

viii. Output of the Given Program

Program Analysis:

int x, y, z1, z2, z3, z4;

x = 18; y = 2;
z1 = x / y; // z1 = 9
z2 = x % y; // z2 = 0
z3 = ++x; // z3 = 19
z4 = y++; // z4 = 2 (post-increment)

Output:

By: Waseem Khan FIC Kohat

z1=9
z2=0
z3=19
z4=2

Alternative Answer

Nested Loop for Multiplication Table:

#include <stdio.h>
int main()
{
for (int i = 1; i <= 3; i++)
{
for (int j = 1; j <= 4; j++)
{
printf("%d x %d = %d\t", i, j, i * j);
}
printf("\n");
}
return 0;
}

ix. Break Statement in Switch Case

Example of Break Statement:

switch (choice) {
case 1: printf("Option 1"); break;
case 2: printf("Option 2"); break;
default: printf("Invalid option");
}

• Break stops further case execution once the correct case executes.

Alternative Answer

Continue Statement:

for (int i = 1; i <= 5; i++)

{
if (i == 3) continue; // Skips iteration when i == 3
By: Waseem Khan FIC Kohat
 printf("%d ", i);
}

x. Define Reserved Words

Definition
Reserved words are keywords predefined in a programming language that have special
meanings and cannot be used for other purposes, like variable names.

Examples: if, while, return.

Alternative Answer

Mathematical Functions:

1. sqrt(x) - Square root.

2. pow(x, y) - Power.
Header File: <math.h>.

xi. Write the Given Statements Using Alternate Syntax

1. Using if-else for k = (a+b>20)? a*3*b : a-b;:

2. if (a + b > 20)
3. k = a * 3 * b;
4. else
5. k = a - b;
6. Using Conditional Operator for if (x>y) {...:
7. z = (x > y) ? (x + y) / 2 : (x - 4 * y);

SECTION C

Answer Key for LONG QUESTIONS Q.3, Q.4, Q.5, and Q.6

Q.3

By: Waseem Khan FIC Kohat

1. Explain the Conditional (Ternary) Operator in C

Explanation
The conditional operator (? :) is a shorthand for the if-else statement. It evaluates a
condition and returns one of two expressions based on whether the condition is true or false.

Syntax

condition ? expression_if_true : expression_if_false;

Example

#include <stdio.h>
int main()
{
int a = 10, b = 20, max;

max = (a > b) ? a : b;

printf("Maximum is: %d", max);

return 0;
}

Comparison with if-else Statement

• Conditional Operator: Compact and suitable for simple conditions.

• If-Else Statement: Easier to read for complex conditions but requires more lines of code.

Equivalent if-else:

if (a > b)
max = a;
else
max = b;

2. Program to Calculate the Area of a Triangle

#include <stdio.h>

int main()
{
float base, height, area;

By: Waseem Khan FIC Kohat

 printf("Enter base and height of the triangle: ");

scanf("%f %f", &base, &height);

area = 0.5 * base * height;

printf("Area of the triangle: %.2f", area);

return 0;
}

Q.4

1. Algorithm to Find the Product of Given Numbers

1. Start.
2. Input the numbers num1 and num2.
3. Calculate the product: product = num1 * num2.
4. Output the product.
5. End.

2. Algorithm to Find the Sum of a Sequence

1. Start.
2. Input the starting and ending numbers of the sequence (start, end).
3. Initialize sum = 0.
4. Loop from start to end:
a. Add the current number to sum.
5. Output the sum.
6. End.

Q.5

1. Purpose of "The Include Preprocessor Directive" in C

The #include directive is used to include external files, such as header files, into a program.
It allows the use of pre-defined functions and macros.

Example:

#include <stdio.h>

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int main()
{
printf("Hello, World!");

return 0;
}

Why Include stdio.h?

The stdio.h header file provides standard input/output functions like printf and scanf.

2. Program to Demonstrate Explicit Typecasting in C

#include <stdio.h>

int main()
{
int a = 5, b = 2;

float result;

result = (float)a / b; // Explicit typecasting

printf("Result: %.2f", result);

return 0;
}

Explanation

• The (float)a convert’s a to a floating-point number before division.

• Without typecasting, integer division would occur, resulting in a truncated value.

Q.6

1. Program to Print the Sum of Squares of Numbers from 1 to 10

#include <stdio.h>

int main()
{
int sum = 0;
By: Waseem Khan FIC Kohat
 for (int i = 1; i <= 10; i++)
{
sum += i * i; // Add square of i to sum
}
printf("Sum of squares: %d", sum);

return 0;
}

2. Program to Calculate Net Pay Based on Basic Pay

#include <stdio.h>

int main()
{
float basicPay, houseRent, netPay;

printf("Enter Basic Pay: ");

scanf("%f", &basicPay);

if (basicPay < 25000)

houseRent = 0.3 * basicPay;

else if (basicPay <= 40000)

houseRent = 0.4 * basicPay;

else
houseRent = 0.5 * basicPay;

netPay = basicPay + houseRent;

printf("Net Pay: %.2f", netPay);

return 0;
}

By: Waseem Khan FIC Kohat