Question 1: Describe in your own words what happens during the fetch stage of the fetch-execute cycle.

Answer: During the fetch stage, the CPU retrieves the next instruction to be executed from the memory address stored in the program counter and stores it in the instruction register.

Question 2: List the main hardware components involved in the fetch-execute cycle and briefly explain their roles.

Answer: Main components include the Control Unit (coordinates operations), the Arithmetic Logic Unit (performs calculations and logic operations), the Memory (stores instructions and data), and the Program Counter (keeps track of the next instruction's address).

Question 3: What is the purpose of the Program Counter in the fetch-execute cycle?

Answer: The Program Counter holds the memory address of the next instruction to be fetched from memory.

Question 4: Explain what happens during the execute stage of the cycle.

Answer: During execution, the CPU carries out the instruction that has been fetched, which may involve calculations, data transfer, or logical operations.

Question 5: Complete the following truth table for an AND logic gate: Inputs A and B, Output Q.

Answer: [{"A":0,"B":0,"Q":0},{"A":0,"B":1,"Q":0},{"A":1,"B":0,"Q":0},{"A":1,"B":1,"Q":1}]

Question 6: Draw a simple logic circuit for an OR gate. Label all inputs and output.

Answer: A correct sketch would show two input lines entering an OR gate symbol (a curved shape with two inputs on the left and one output on the right), with the inputs labeled A and B, and the output labeled Q.

Question 7: Sketch a diagram of a basic computer system showing the connection between the CPU, memory, and input/output devices. Label each component clearly.

Answer: The diagram should include the CPU in the centre, connected via buses to the memory unit, and separate connections to input devices (like a keyboard) and output devices (like a monitor).

Question 8: Identify and describe two types of memory used in a computer system.

Answer: RAM (Random Access Memory) is volatile memory used for temporary data storage while the computer is on. ROM (Read-Only Memory) is non-volatile memory that stores permanent instructions, such as the BIOS.

Question 9: Explain why the fetch-execute cycle is important for a computer to run programs.

Answer: The fetch-execute cycle allows the CPU to systematically retrieve, interpret, and perform instructions, enabling the computer to run programs sequentially and perform tasks.

Question 10: Describe what happens if the Program Counter is not correctly updated during the fetch stage.

Answer: If the Program Counter is not correctly updated, the CPU may fetch the wrong instruction, leading to errors, crashes, or unpredictable behaviour in the program execution.

Question 11: Draw a flowchart to illustrate the sequence of the fetch-execute cycle. Use arrows to connect each step in order.

Answer: A correct flowchart would include the steps: Fetch instruction from memory, decode instruction, execute instruction, and then repeat the cycle. Arrows should clearly connect these steps in order.