Question

An electric bulb is rated 220v and 100 w.Power consumed by when 110 volt is

Answer 1

Power=100W.........given

P.D=220V.......given

Therefore,

P=V²/R

So, R=V²/P

So, R=(220)²/100

So, R=48400/100

So, R=484ohm

Now Resistance is same

So, now

R=484ohm

V=110

Therefore

P=V²/R

So, P=(110)²/484

So, P=12100/484

So, P=25W

Therefore Power at 110V is 25watt