Question

A sinusoidal alternating current of peak value $I_0$ passes through a heater of resistance $R$. What is the mean power output of the heater?

• A. $I_0^{2}R$
• B. $\frac{I_0^{2}R}{2}$
• C. $2I_0^{2}R$
• D. $\sqrt{2}{I}_0^{2}R$

Answer 1

The correct option is B $\frac{I_0^{2}R}{2}$

Power of A.C. is always calculated with rms value.
RMS Current $I_{RMS}=\frac{I_o}{\sqrt{2}}$
Power $={I_{RMS}}^{2}R=\frac{{I_o}^{2}R}{2}$