Question

Two bulb of 60 watt and 100 volt and 100 watt 200 volt are joiend in series and connected to 220 volt mains calculate current

Answer 1

P=VI;---------------------------------------------------------------POWER RATING

60=I*100;

I=0.6 A;

therefore, resistance=V/I;----------------------------------OHM'S LAW

R=100/0.6;

R=166.67;

I round the value and take it as 167 ohms;

the same process is done for the other bulb and the resistance for it is 400 ohms;

so if the resistors are connected in series the sum is the equivalent resistance;

R1+R2=167+400=567 ohms;

so the current=220/567;

I=0.3880.....;

therefore current is equal to 0.39 amperes;