An electric bulb rated 100 W at 200 V is connected to a 160 V power supply. The power consumed by it would be:
Answer & explanation
Correct answer: option 1
The correct answer is Option (1) → 64 W
The power consumed,
$P=\frac{V^2}{R}$
$⇒R=\frac{V^2}{P}=\frac{(200)^2}{100}=400Ω$
Now the bulb is connected to 160 V power supply.
$P=\frac{V^2}{R}=\frac{(160)^2}{400}=64W$