Power of Electrical Circuit: Practice Problem & Solution

Solution Explained:

To solve this problem, we apply the core principles of Power of Electrical Circuit. Understanding the underlying formula is key to arriving at the correct answer below:

Power is given by $P = \frac{V^2}{R}$. For small changes, the fractional change is $\frac{\Delta P}{P} = 2\frac{\Delta V}{V}$. The percentage decrease in power will be $2 \times 2.5\% = 5\%$.