Q2Basic Electrical Engineering

Apparent Power (S): It is the product of the Root Mean Square (RMS) voltage and RMS current in an AC circuit, without taking the phase angle into consideration. It represents the total power capacity that must be supplied by the source. It is denoted by 'S' and measured in Volt-Amperes (VA) or kVA. $S=V_{rms}\times I_{rms}$.

Power Factor (pf): It is fundamentally defined as the ratio of the true or active power ($P$) consumed by the circuit to the apparent power ($S$) supplied to it. It indicates how effectively electrical power is being converted into useful work output. Mathematically, it is also the cosine of the phase angle ($\varphi$) between the voltage and current waveforms. $pf=\cos (\varphi )=P/S$.