Question

An electricity bulb of 100 watt is connected to supply of electricity of 220V. Resistance of filament is

• A. $484\Omega$
• B. $100\Omega$
• C. $22000\Omega$
• D. $242\Omega$

Answer 1

Answer: (A)

$484\Omega$

Given : $V=220$ volts $P=100$ W

$\therefore$ Resistance of the filament $R=\frac{V^2}{R}$

$⟹$ $R=\frac{{220}^2}{100}=484\Omega$