Nate Electrical Practice Exam

What happens to the power when the voltage is doubled while keeping resistance the same?

1. Double

2. Triple

3. Quadruple

4. Remain the same

The correct answer is: Quadruple

When the voltage is doubled while keeping the resistance constant, the power increases, specifically quadrupling. This can be understood through the power formula in electrical circuits, which is defined as \( P = \frac{V^2}{R} \). Here, \( P \) represents power, \( V \) is voltage, and \( R \) is resistance. If the initial voltage is \( V \) and the resistance remains the same, we can express the initial power as \( P = \frac{V^2}{R} \). When the voltage is doubled, the new voltage becomes \( 2V \). Plugging this into the power formula gives us: \[ P' = \frac{(2V)^2}{R} = \frac{4V^2}{R} \] This means that the new power \( P' \) is four times the initial power (\( P' = 4P \)). Consequently, whenever the voltage is doubled, the result is that the power quadruples, which is why this choice is correct.