Question

21. An electric lamp is marked 2 points
240V, 60W. What is its
resistance (?) when it is
operated at the correct
voltage?
O A. 1/960
O B. 1/4
O 0.4
O D. 960​

Answer 1

Answer:

The resistance of the lamp is 960 ohms.

Explanation:

We have,

Voltage of electric lamp is 240 V and power is 60 W.

It is required to find the resistance of the lamp.

The power of an electrical device is given by :

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

R is resistance

$R=\dfrac{V^2}{P}\\\\R=\dfrac{(240)^2}{60}\\\\R=960\ \Omega$

So, the resistance of the lamp is 960 ohms.