A 220-$\varOmega$ resistor is connected across an ac voltage source V = (150 V) sin [2$\pi$(60 Hz)t]. What is the average power delivered to this circuit?
A)51 W
B)110 W
C)280 W
D)320 W
E)550 W

Question

Quizplus · Accepted Answer

The average power delivered to a resistor in an AC circuit is given by $ P = \frac{V_{rms}^2}{R} $. The RMS voltage $ V_{rms} $ is $ \frac{V_{peak}}{\sqrt{2}} $, where $ V_{peak} = 150 \, V $. Thus, $ V_{rms} = \frac{150}{\sqrt{2}} \approx 106.07 \, V $. Therefore, the average power is $ P = \frac{106.07^2}{220} \approx 51 \, W $.

A 220- Ω\varOmegaΩ Resistor Is Connected Across an Ac Voltage Source V =

A 220- $\varOmega$ Resistor Is Connected Across an Ac Voltage Source V =