What is the role of the Central Processing Unit (CPU) in a computer?

• It stores data and instructions.

• It executes instructions and performs calculations.

• It allows communication with external devices.

• It performs arithmetic and logical operations.

Answer explanation

The Central Processing Unit (CPU) is essentially the brain of a computer. Its primary role is to execute instructions that make up computer programs. the CPU coordinates and executes all operations within a computer system, making it a crucial component for computing tasks of all kinds, from simple calculations to complex computations and multitasking.

What does the memory unit do in a computer?

• It stores data and instructions currently being used.

• It executes instructions.

• It directs the flow of data.

• It allows communication with external devices.

Answer explanation

The memory unit in a computer is responsible for temporarily storing data and instructions that the CPU is currently processing. It provides fast access to essential information needed for execution. The most common type of memory unit is RAM (Random Access Memory), which holds active programs and data but loses its contents when the computer is powered off

Logical units in a computer, some of which include...

(Select all correct answers)

• Arithmetic and Logic Unit (ALU), Control Unit (CU)

• Input/Output Unit

• Power Supply Unit (PSU)

• Storage Unit

• Graphics Processing Unit (GPU)

Answer explanation

The Power Supply Unit (PSU) is a hardware component that provides electrical power to the computer. It does not perform data processing or logical operations. The Graphics Processing Unit (GPU) is a specialized processor for rendering images, videos, and graphical computations. Although it performs calculations, it is not considered a fundamental logical unit like the ALU, CU, or storage unit.

What is an algorithm?

• A type of computer hardware component.

• An algorithm is a step-by-step procedure for solving a problem.
• A random guess without any steps.
• A recipe for cooking a meal.

Answer explanation

An algorithm is a well-defined set of instructions designed to perform a specific task or solve a problem. It follows a logical sequence of steps that can be implemented in programming languages to automate processes. Algorithms are fundamental in computer science and can be used for tasks like sorting, searching, and decision-making.

Which of the following is one of the requirements of a good algorithm?

• A good algorithm must have well-defined inputs and outputs.

• A good algorithm should be complex to solve problems efficiently.

• It should only focus on speed without considering accuracy.
• A good algorithm must be written in a programming language.

Answer explanation

A good algorithm should meet several key requirements, and one of them is having well-defined inputs and outputs. This ensures that the algorithm can process given data correctly and produce meaningful results. Algorithms can be expressed in pseudocode or flowcharts before implementation. Simplicity is often preferred if it achieves the desired outcome effectively.

What is algorithm notation?

• Algorithm notation is a method for writing code.
• A set of rules for executing an algorithm on a computer.

• Algorithm notation is a symbolic or structured way to represent an algorithm.

• Algorithm notation is a type of programming language.

Answer explanation

Algorithm notation refers to the formal or structured way of writing algorithms so that they can be understood and implemented correctly. It helps describe the steps of an algorithm in a clear and logical manner. Common forms of algorithm notation include: Pseudocode and Flowcharts.

What is a flowchart?

• A programming language used to implement algorithms.

• A diagram that represents the steps of an algorithm using symbols.

• A type of software that executes algorithms automatically.

• A mathematical symbols used to solve complex problems.

Answer explanation

A flowchart is a graphical representation of an algorithm that uses standardized symbols to illustrate the sequence of steps in a process. It helps visualize logic flow, making it easier to understand and analyze an algorithm.

What is a variable?

• A variable is a symbolic name for a value that can change.
• A variable is a fixed memory location for storing data.
• A variable is a type of data structure that holds multiple values.
• A variable is a constant value that cannot change.

Answer explanation

A variable is a storage location in a computer program that holds a value, which can be modified as the program runs. Variable has name (identifier), data type, and a value.

Which of the following are the rules for naming variables in C programming languages?

(Select all correct answers)

• Can start with a number.

• Cannot contain spaces.

• Cannot use reserved keywords or built-in functions.

• Case-Sensitive.

• Allowed Characters: Variable names can only consist of letters (A-Z, a-z), numbers (0-9), and underscores (_).

Answer explanation

• Variable names cannot start with a number in most programming languages such as Python, Java, C, C++, and JavaScript.

• A variable name must begin with a letter (A-Z, a-z) or an underscore (_). Numbers (0-9) are allowed but cannot be the first character.

Which of the following are valid variable names in programming? (Select all correct answers)

• user_name

• 2ndValue

• _dataCount

• int

• totalAmount$

Answer explanation

Explanation:

✅ user_name: Valid because C allows variable names to contain letters, numbers, and underscores (_), but they cannot start with a number.

❌ 2ndValue: Invalid because in C, variable names cannot start with a number.

❌ totalAmount$: Invalid because the dollar sign ($) is not allowed in C variable names.

✅ _dataCount: Valid because variable names can start with an underscore (_) in C.

❌ int: Invalid because int is a reserved keyword in C and cannot be used as a variable name.