How do you calculate power in an AC circuit?

Power in an AC circuit can be calculated using the formula P = VIcosθ.

In an AC circuit, power is the rate at which energy is transferred from the source to the load. The power delivered to the load is given by the product of the voltage and current, P = VI. However, in an AC circuit, the voltage and current are not always in phase with each other, which means that some of the power is not transferred to the load. This is known as reactive power, which is measured in volt-amperes reactive (VAR).

To calculate the actual power delivered to the load, we need to take into account the phase difference between the voltage and current. This is given by the power factor, which is the cosine of the angle between the voltage and current waveforms. The power delivered to the load is then given by P = VIcosθ, where θ is the phase angle.

The power factor can be improved by adding a capacitor or an inductor to the circuit, which will compensate for the reactive power and bring the voltage and current into phase. This is known as power factor correction.

In summary, power in an AC circuit can be calculated using the formula P = VIcosθ, where θ is the phase angle between the voltage and current waveforms. Power factor correction can be used to improve the power factor and reduce the amount of reactive power in the circuit.