Explanation:

When wattless current flows in an AC circuit, it indicates that the circuit is purely inductive. Let's understand why this is the case.

AC Circuit:
An AC circuit consists of different components such as resistors, inductors, and capacitors. These components can affect the flow of current in different ways.

Wattless Current:
Wattless current refers to the current that does not consume any power. It is also known as reactive current or imaginary current. This current occurs in inductive and capacitive circuits.

Purely Resistive Circuit:
In a purely resistive circuit, the current and voltage are in phase with each other. This means that the current reaches its maximum value at the same time as the voltage. In this case, the power consumed by the circuit is real power, and there is no reactive power.

Purely Inductive Circuit:
In a purely inductive circuit, the current lags behind the voltage by 90 degrees. This means that the maximum value of current occurs after the maximum value of voltage. In this case, the power consumed by the circuit is reactive power, and there is no real power.

LCR Series Circuit:
An LCR series circuit consists of an inductor, capacitor, and resistor connected in series. In this circuit, the current can be a combination of real and reactive components. The phase relationship between current and voltage depends on the values of the inductor, capacitor, and resistor.

RC Series Circuit Only:
In an RC series circuit, the current can also be a combination of real and reactive components. The phase relationship between current and voltage depends on the values of the resistor and capacitor.

Conclusion:
When wattless current flows in an AC circuit, it indicates that the circuit is purely inductive. This means that the current lags behind the voltage by 90 degrees, and the power consumed by the circuit is reactive power.