Question

two electric lamps rated 100W, 220V and 25W,220V are connected in parallel to a 220V supply. Calculate the total electrical current in the circuit

Answer 1

Now we have a little bit of calculation stuff here.

We have two bulbs connected across a 220V supply.And we shall use these formulaes

P=(V2)/R So R=(V2)/P and P=IV

Bulb A: P=2ooW,V= 220V.

R1=(220∗220)/200=242ohm

Bulb B: P=1ooW,V= 220V.

R2=(220∗220)/100=484ohm

Total Current= I=V/(R1+R2)

I=220/726=0.3Amp

Potential Difference across 1V1=I∗R1=0.3∗484=146.6V

Potential Difference across 2 V2=I∗R2=0.3∗242=73.3V

FinallyP1=I∗V1=o.3∗146.6=22.2W

And P2=I∗V2=o.3∗73.3=44.4W

So Power consumed by Bulb A is 22.2W , And Bulb B consumes 44.4W