Question

In a circuit containing resistance only, voltage and current are ______.

Options

• In phase

• Out of phase by 180°

• Out of phase by 120°

• Out of phase by 90°

Answer 1

In a circuit containing resistance only, voltage and current are in phase.

Explanation:

The electrical current that flows through an AC resistance varies sinusoidally with time and is represented by the expression, I(t) = I sin(ωt + θ)

Now by ohm's law, V = IR

So, for the AC circuit, V = IR sin(ωt + θ)

In a circuit containing resistance only, both V and I have zero phase difference and hence are in phase.