An electric bulb rated $50 \mathrm{~W}-200 \mathrm{~V}$ is connected across a 100 V supply. The power dissipation of the bulb is :

JEE Main · 2024 · 04 Apr 2024 · Shift 2 · Current Electricity

An electric bulb rated

50 W - 200 V

is connected across a 100 V supply. The power dissipation of the bulb is :

Answer: (A)

Rated resistance of the bulb from its label:

R = \frac{V ^{2}}{P} = \frac{20 0 ^{2}}{50} = 800 Ω

.
Since filament resistance is treated as constant, the power drawn from a 100 V supply is:

P^{'} = \frac{V ^{'2}}{R} = \frac{10 0 ^{2}}{800} = 12.5 W

JEE Main · 2024 · 04 Apr 2024 · Shift 2 · Single correct option