NABCEP Solar Associate Practice Exam

The formula to determine voltage (V) when you have the power in watts (W) and the current in amperes (I) is derived from the fundamental electrical relationship defined by Ohm's Law and the power formula.

Power (P) is calculated using the formula \( P = V \times I \). To isolate voltage in this equation, you can rearrange the formula to solve for V. Dividing both sides by current (I) gives you:

\[ V = \frac{P}{I} \]

Since power is measured in watts (W), this can be rewritten as:

\[ V = \frac{W}{I} \]

This shows that voltage is equal to the power in watts divided by the current in amperes. Therefore, the correct formula for finding voltage when known power and current values are provided is V = W/I.

This fundamental relationship is crucial to understanding how electric circuits operate, enabling you to calculate voltage in scenarios involving various electrical components.