Question

an electric meter is rated 1.5 kw 220 watts .find the save current which can pass through it

Answer 1

Firstly we calculate the resistance of the bulb,

According to Ohm’s Law

R=V/I Where,R=Resistance , V=Voltage ,I=Current..

100w at 220v, I=P/V.

=100/220=0.454Amp.

R=V/I; 220/0.454=484.56 ohms.

When it is connected to 240 Volts

I=V/R; 240/484.56=0.495 ~ 0.50 Amps.

Power consumed(P)=V×I; 240×0.50=120 W.

The bulb will consume 120 W at 240 Volts. 20W difference.

This is not a loss the bulb glows brighter than it used in 220 volts..