Chapter 26, Problem 1CQ

To determine

In which of the two circuits does the resistor dissipate greater average power.

Answer to Problem 1CQ

In both the circuits the resistor dissipate same average power.

Explanation of Solution

Write the expression for average power in ac circuit.

    $P_{\text{R}}=\frac{V_{\text{rms}}^2}{R}$        (I)

Here, $P_{\text{R}}$ is the average power, $V_{\text{rms}}$ is the rms voltage, and $R$ is the resistance.

From equation (I), it is very clear that the average power is independent of frequency and both the resistors are connected to the same $12\text{V}$ AC source, thus the resistor dissipate same average power in both the circuit.

Conclusion:

Therefore, in both the circuits the resistor dissipate same average power.