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In an AC circuit with voltage \(V\) and current \(I\), the power dissipated is

1. \(VI\)
2. \(\frac{VI}{2}\)
3. \(\frac{VI}{2}\)
4. Depends on the phase between \(V\) and \(I\)

Correct answer: Depends on the phase between \(V\) and \(I\)

Solution

The average power in an AC circuit is \(P = V_{\text{rms}} I_{\text{rms}} \cos\phi\). Therefore, it depends on the phase difference \(\phi\) between voltage and current. Only when \(\phi = 0\) is the power maximum and equal to \(VI\).

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