Q$9$ If the input voltage is a sinusoidal waveform, $v_{ac}(t)=\sqrt[\phantom{2}]{2}cost,$ and the input current, $i_{ac}(t),$ is a square waveform shown below,

It is known that the $i_{ac}$ distortion components $($not including the fundamental component$)$ can be expressed as

$i_{ac}(t)=-\frac{4I_m}{3}cos(3t)+\frac{4I_m}{5}cos(5t)-+$cdots

please calculate:

Displacement power factor $($DPF$)$

Real power $P_{ac,\text{a}\text{v}\text{e}}$

Power factor PF

Total harmonic distortion $($THD$)$