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In a circuit, the instantaneous current and voltage are expressed by
i = (1/√2) sin(100πt) A
e = (1/√2) sin(100πt + π/3) V
What is the average power, in watts, dissipated in the circuit?
- 1/4
- √3/4
- 1/2
- 1/8
Correct answer: 1/8
Solution
The average power in an AC circuit can be calculated using the formula P = Vrms * Irms * cos(φ), where φ is the phase difference between voltage and current. In this case, the phase difference is π/3, leading to a power factor of cos(π/3) = 1/2, and with the given rms values, the average power evaluates to 1/8 watts.
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