Question 1: Resistance is a measure of how much a material opposes the flow of electric current. It depends on the material's properties, length, and cross-sectional area. The unit of resistance is the Ohm (Ω).

Answer: Resistance measures how much a material opposes the flow of electric current and is measured in Ohms (Ω).

Question 1: Define electrical resistance.

Answer: Electrical resistance is the opposition that a material offers to the flow of electric current.

Question 2: List three factors that affect the resistance of a wire.

Answer: Material type, length of the wire, and cross-sectional area.

Question 1: A circuit has a voltage of 12 volts and a current of 3 amperes. Calculate the resistance of the wire.

Answer: Resistance = 12 V / 3 A = 4 Ω

Question 2: If a resistor has a resistance of 10 Ω and a current of 2 amperes flows through it, what is the voltage across it?

Answer: Voltage = Resistance × Current = 10 Ω × 2 A = 20 V

Question 1: Describe a simple experiment to investigate how the length of a wire affects its resistance.

Answer: Select a wire of a known material, connect it in a circuit with a voltmeter and ammeter. Measure the current for different lengths of the same wire (e.g., 10 cm, 20 cm, 30 cm). Record the voltage and current at each length. The resistance can be calculated using R = V / I. Expect resistance to increase as the length of the wire increases.

Question 2: Identify two safety precautions to observe when conducting an experiment involving electrical resistance.

Answer: Ensure the circuit is not connected to a high voltage source, and handle wires and connections carefully to avoid short circuits or electric shocks.

Question 1: A student measures the resistance of a copper wire to be 0.5 Ω when its length is 1 meter. When the length is increased to 3 meters, what is the expected resistance? Explain your reasoning.

Answer: Resistance is directly proportional to length. Therefore, resistance at 3 meters = 0.5 Ω × 3 = 1.5 Ω.

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

Answer: Understanding resistance helps in selecting appropriate wire thickness and material to ensure safety, prevent overheating, and reduce energy loss. Proper resistance management ensures efficient and safe electrical systems in homes.

Question 2: Identify a technological device or industry where controlling resistance is crucial and explain why.

Answer: In electronic circuits, controlling resistance is crucial to prevent overheating and ensure accurate functioning of components like resistors, transistors, and integrated circuits.