KEAM 2021 Physics and Chemistry Solved Paper

Average power dissipated in an AC circuit is given as
Pav=Vrmsirms‌cos‌φ
where, Vrms and irms are the rms value of voltage and current respectively and cos‌φ is the power factor.
The circuit gives maximum power dissipation, i.e. the voltage and current are in same phase, so phase difference is zero, or power factor is maximum, which occurs only in resistive circuit.
So, the circuit that gives maximum power dissipation is purely resistive circuit.