Why the product of the RMS voltage and the RMS current the apparent power is always higher than the real power in diode rectifier circuits

In diode rectifier circuits, the current flows in pulses as the diodes allow current to flow only in one direction. The voltage waveform is also not a perfect sinusoidal waveform. Therefore, the RMS voltage and current are not in phase with each other, resulting in a power factor less than 1.

The product of the RMS voltage and current (apparent power) is the total power consumed by the circuit. However, due to the power factor being less than 1, the actual power delivered by the circuit (real power) is lower than the apparent power. The real power is the power that is actually used by the load and is calculated as the product of the RMS voltage, RMS current, and the power factor.

In diode rectifier circuits, the power factor is typically low due to the non-sinusoidal waveforms and the phase difference between the voltage and current. Therefore, the apparent power is higher than the real power