Question

what will be the current Drawn by a lamp rated to 250v ,40watts connected to a 230v supply​

Answer 1

Answer:

I=0.1472 A

Explanation:

First, we need to find the resistance of the lamp when it is rated to 250V/40W.

We know that P=$V^{2}$/R

R=$V^{2}$/P  == $250^{2}$/40

R=1562.5Ω

Since, the voltage supply is only 230V, so the current drawn by the lamp is calculated using Ohm's Law:

I=V/R

I=230/1562.5

I=0.1472 A