Question

In an AC circuit, the current is;
A) Is in phase with the voltage
B) Leads the voltage
C) Lags the voltage
D) Any of the above depending on the circumstances

Answer 1

Hint:In AC circuits, the value of the magnitude and direction of current and voltages is not constant, it changes at a regular interval of time. It travels as a sinusoidal wave completing one cycle as half positive and half negative cycle and is a function of time or angle.

Complete solution
An AC circuit is the circuit which is excited using an alternating source. The components of AC circuits are Resistor, Capacitor, and the inductor. These passive components have one thing in common, they limit the flow of electrical current through a circuit but in different ways. The resistance to the flow of current in an RLC circuit is known as impedance $\left( {\rm Z} \right)$

If the direction of the current in a resistor or in any other element changes its direction alternately, the current is called an alternating current.

When the capacitance is introduced in the circuit, the current leads the voltage then the power factor is leading. When inductance is introduced in the circuit, the voltage and current will be out, the current lags the voltage. In a resistive circuit, there is no coil, no emf is induced hence it follows the sine wave as like the source voltage that is current is in phase with the voltage.

Current may depend upon any circumstances. It may lead the voltage or in phase of voltage or lags the voltage.
NOTES:In an AC circuit, the current varies sinusoidal. In an alternating current, electrons do not flow in one direction because the potential of the terminals vary between high and low. Thus electrons move to and fro in the wire carrying alternating current.