Question

 An electric bulb is rated at 200 V, 40 W. Find it's resistance​

Answer 1

$\underline{\underline{\sf\bf\bigstar\huge ANSWER \bigstar}}$

Given ,

Voltage , V = 200V

 Power , P =  40W

$\sf \longrightarrow \boxed{\bf P=\dfrac{V^2}{R}}$

$\sf\Longrightarrow 40=\dfrac{200\times200}{R}\\\\\Longrightarrow R = \dfrac{200\times200}{40}\\\\\Longrightarrow\bf R = 1000 \ ohm$

Resistance = 1000 Ω

HOPE IT HELPS U ..... :)