Question

Two appliances rated as (60 W, 200 V) and (40 W, 200 V) are connected across a 100 V supply in a room. The total power consumed is

• A. 25 W
• B. 10 W
• C. 15 W
• D. None of these \bigskip

Hint:

When voltage is different from the rated voltage, use \( P = \frac{V^2}{R} \) to calculate actual power consumption.

Answer 1

The Correct Option is A

The power consumption at a different voltage can be calculated using: \[ P = \frac{V^2}{R} \] For the first appliance, the resistance \( R = \frac{200^2}{60} \approx 666.67 \, \Omega \) and for the second appliance \( R = \frac{200^2}{40} = 1000 \, \Omega \). Calculating the power at 100V for both: \[ P_1 = \frac{100^2}{666.67} \approx 15 \, W \quad \text{and} \quad P_2 = \frac{100^2}{1000} = 10 \, W \] Total Power = \( 15 \, W + 10 \, W = 25 \, W \).