Question

Find out the resistance of the filament of a bulb which is labelled as '240V 40W'?only from the options.....plsssss
. 1000 ohm
. 1440 ohm
. 5760 ohm
. 960 ohm​

Answer 1

Answer:

Given:

Voltage Rating = V = 240 Volts

Power (P)= 40 Watts

To Find:

Resistance (R)

Solution:

We know that,

$\boxed{\rm P = V \times I}$

Therefore,

$\rm \implies I = \dfrac{P}{V}$

$\rm \implies I = \dfrac{40}{240}$

$\rm \implies I = 0.167 \;A$

Here we need to to find the Resistance (R)

$\boxed{\rm R = \dfrac{V}{I} }$

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

$\rm \implies R = \dfrac{240^2}{40}$

$\implies \rm R= 1440$ Ω

Correct answer is 1440 Ω