Question 1: Define electrical resistance and explain its effect on current flow in a circuit.

Answer: Electrical resistance is a measure of how much a material opposes the flow of electric current. Higher resistance reduces current flow in a circuit.

Question 2: Describe the role of resistors in an electronic circuit.

Answer: Resistors limit or control the amount of current flowing through a circuit by providing a specific resistance.

Question 1: A circuit has a current of 2 A flowing through a resistor of 10 Ω. Calculate the potential difference across the resistor. (Use V = IR)

Answer: V = 20 V

Question 2: A wire has a resistance of 5 Ω. If the current flowing through it is 3 A, what is the potential difference across the wire?

Answer: V = 15 V

Question 1: Describe a simple experiment to measure the resistance of a wire, including the variables that need to be controlled.

Answer: To measure resistance, set up a circuit with a power supply, the wire, an ammeter, and a voltmeter. Vary the length of the wire and record voltage and current. Control variables such as wire material, temperature, and thickness to ensure accurate results.

Question 2: List two safety precautions to observe when working with electrical circuits involving resistors.

Answer: Ensure the circuit is powered off before making adjustments, and avoid touching live wires to prevent electric shocks.

Question 1: A wire of constant material and diameter has its length increased from 1 meter to 3 meters. Describe how this change affects its resistance and explain why.

Answer: Increasing the length of the wire increases its resistance because resistance is directly proportional to length (R ∝ L). Longer wires provide more opposition to current flow due to the greater amount of material the current must pass through.

Question 1: Explain how understanding resistance is important in designing household wiring and appliances.

Answer: Understanding resistance helps in selecting appropriate wire thickness and materials to prevent overheating, ensure safety, and optimise energy efficiency in household wiring and appliances.