Question

Why is power delivered to an AC circuit not simply the product of voltage and current magnitudes?

Options

• Voltage varies sinusoidally, but current is always constant.

• Both voltage and current vary sinusoidally and are often out of phase.

• Current varies sinusoidally, but voltage is always constant.

• Voltage and current are always in phase.

Answer 1

In an AC circuit, voltage and current both vary sinusoidally. Their phase difference affects the average power delivered to the circuit.