Question

When an AC voltage is applied to a pure resistor, the current and voltage are ______.

Options

• Current leads voltage by 90°

• Voltage leads current by 90°

• In phase with each other

• Out of phase by 180°

Answer 1

When an AC voltage is applied to a pure resistor, the current and voltage are in phase with each other.

Explanation:

In a pure resistor, both voltage v = v_m sin⁡ ωt and current i = i_m sin⁡ ωt follow the same sinusoidal pattern. They reach their zero, minimum, and maximum values at exactly the same time, meaning they are perfectly in phase.