Question

15. (a) Name a device that helps to measure the potential difference across a conductor.

(b) How much energy is transferred by a 12 V power supply to each coulomb of charge which it moves around a circuit ?​

Answer 1

(a) A device that helps measure the potential difference across a conductor is called a "voltmeter."

(b) A 12 V power supply transfers 12 joules of energy to each coulomb of charge that it moves around a circuit.

Answer 2

(a) Voltmeter is used to measure the potential difference across a conductor. Voltmeter is also known as voltage meter.

(b) To calculate the energy transferred we can use the equation of work done.

• Work done = qv

Where,

• q denotes charge in Coulomb
• v denotes potential difference in volts.

On solving we get,

Work done = 1 × 12

Work done = 12 Joules

Hence 12 Joules energy is transferred 12 V power supply to each coulomb of charge which it moves around a circuit

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