Answer
a. 1500W.
b. 3000W. 0 W.
Work Step by Step
a. Use Equation 18–9c to find the average power.
$$\overline{P}=\frac{V_{rms}^2}{R}$$
$$\overline{P}=\frac{(240V)^2}{38\Omega}=1516W\approx 1.5\times10^3 W$$
b. See Figure 18-22. The maximum instantaneous power is twice the average power. The maximum is $3.0\times 10^3 W$.
See Figure 18-22. The minimum instantaneous power is zero.