Question 1: Convert the decimal number 25 into an 8-bit binary number.

Answer: 00011001

Question 2: Convert the binary number 110101 to decimal.

Answer: 53

Question 3: Write the binary equivalent of the decimal number 128.

Answer: 10000000

Question 4: Explain why computers use binary to represent data instead of decimal numbers.

Answer: Computers use binary because digital circuits have two states (on and off), making binary a simple and reliable way to represent data with high accuracy and minimal errors.

Question 5: Complete the truth table for an AND logic gate with two inputs, A and B:

Answer: A | B | Output ---|---|-------- 0 | 0 | 0 0 | 1 | 0 1 | 0 | 0 1 | 1 | 1

Question 6: Complete the truth table for an OR logic gate with two inputs, A and B:

Answer: A | B | Output ---|---|-------- 0 | 0 | 0 0 | 1 | 1 1 | 0 | 1 1 | 1 | 1

Question 7: Draw a logic circuit that uses two AND gates and one OR gate to combine three inputs, A, B, and C. Label each gate accordingly.

Answer: A correct sketch would show two AND gates with inputs A and B going into the first, inputs B and C into the second, and the outputs of both AND gates feeding into an OR gate, with the final output coming from the OR gate.

Question 8: Describe what happens to the output of an NOT (inverter) gate when the input is high (1).

Answer: The output becomes low (0).

Question 9: Sketch a simple circuit diagram that includes a switch, a light bulb, and a battery in series. The switch should control whether the bulb lights up.

Answer: A correct sketch would show a battery connected in series with a switch and a light bulb, with the switch in the circuit so that closing the switch completes the circuit and lights the bulb.

Question 10: What is the binary representation of the decimal number 7? Write your answer using 4 bits.

Answer: 0111

Question 11: Explain why binary is suitable for use in digital electronic devices.

Answer: Binary is suitable because digital devices rely on two distinct states (on and off), which are easy to represent electronically with high reliability, stability, and low error rates.