Question

Twobulbsmarked200watt-220voltand100watt-220voltarejoined

inseriestoa220voltsupply.Powerconsumedinthecircuitisabout

(A)33watt(B)67watt(C)100watt(D)300watt.​

Answer 1

Answer:

Bulb 1 ratings are 200 watts and 220 volts

Bulb 2 ratings are 100 watts and 220 volts

And these two bulbs are connected in series with 220 volts supply

First find the current rating of bulb 1

We know that P=VI1

I1= 200/220

I1=0.91 A, R1= v/I= 220÷0.91=241.76ohm

Do Same as bulb 2

I2=100/220

I2=0.45A= R2= 220/0.45=488.89ohm

In series connection the resistance should be added

R1+R2= 241.76+488.89

=730.65 ohms

Total power consumed by the circuit is given by

P= (V*V)/R

(220*220)/(730.65)=66.24watts

Therefore total power consumed by the circuit is 66.24watts

Ans: B