Question

What is the resistance, under normal working conditions of a $240V$ electric lamp rated at $60W$?

• A. $960\Omega$
• B. $400\Omega$
• C. $60\Omega$
• D. $15\Omega$

Answer 1

The correct option is A $960\Omega$

$P=\frac{V^2}{R}$

Given that the voltage is $240V$ and the power is $60W$, the resistance of the bulb is calculated as follows.

$R=\frac{V^2}{P}=\frac{{240}^2}{60}=960\Omega$