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:

Resistance of the bulb $R = \frac{V^2}{P} = \frac{200^2}{100} = 400\Omega$. The power consumed at $160\text{ V}$ is $P' = \frac{V'^2}{R} = \frac{160^2}{400} = 64\text{ W}$.