Question 1: Define electric current and explain how it flows in a circuit.

Answer: Electric current is the rate of flow of electric charge through a conductor, measured in amperes (A). It flows from the positive to the negative terminal in a circuit, driven by a voltage difference.

Question 2: Describe the role of a resistor in a circuit with regard to current flow.

Answer: A resistor limits the flow of current in a circuit by providing resistance, which reduces the amount of charge passing through per second.

Question 1: Calculate the current flowing through a circuit if a voltage of 12 V is applied across a resistor of 6 Ω. Use the formula I = V / R.

Answer: Current (I) = 12 V / 6 Ω = 2 A

Question 2: A circuit has a current of 3 A and a resistance of 4 Ω. What is the voltage supplied to the circuit? Use V = I × R.

Answer: Voltage (V) = 3 A × 4 Ω = 12 V

Question 1: List three variables you would need to control in an experiment measuring current in a circuit.

Answer: Voltage supplied, resistance of the resistor, and temperature of the circuit components.

Question 2: Identify two safety precautions to observe when working with electrical circuits.

Answer: Ensure the circuit is switched off before assembling, and avoid touching live wires to prevent electric shocks.

Question 1: A student measures a current of 0.5 A in a circuit powered by a 9 V battery. If the resistance of the circuit is found to be 18 Ω, does this data support Ohm's Law? Explain your reasoning.

Answer: Yes, it supports Ohm's Law because using V = IR, V = 0.5 A × 18 Ω = 9 V. The calculated voltage matches the battery voltage, confirming the law.

Question 1: Explain how increasing resistance in a circuit affects the current, assuming voltage remains constant.

Answer: Increasing resistance decreases the current flow in the circuit because resistance opposes the movement of charge, as described by Ohm's Law.

Question 2: A circuit with a resistance of 10 Ω is connected to a 20 V power supply. Calculate the current in the circuit.

Answer: I = V / R = 20 V / 10 Ω = 2 A

Question 3: Describe the purpose of a fuse in an electrical circuit in relation to current.

Answer: A fuse protects the circuit by breaking the flow of current if it exceeds a safe level, preventing damage or fire.

Question 4: A device requires a current of 5 A to operate correctly. If the supply voltage is 25 V, what is the resistance of the device?

Answer: Resistance R = V / I = 25 V / 5 A = 5 Ω

Question 1: Explain how understanding current is important in designing electrical safety systems in household wiring.

Answer: Understanding current helps engineers design circuits that include safety features like circuit breakers and fuses to prevent overloads and potential fires.

Question 2: Describe one way in which current measurement is critical in renewable energy technology, such as solar panels or wind turbines.

Answer: Current measurement is vital to determine the power output of solar panels or wind turbines, ensuring optimal operation and efficiency.