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:

In series, $P_{\text{series}} = \frac{P}{3} = 10\text{ W}$, so the power of each bulb is $P = 30\text{ W}$. When connected in parallel, $P_{\text{parallel}} = 3P = 3 \times 30 = 90\text{ W}$.