Question

A 40 watt lamp requires 0.182 A of current at 220 Volts, while a 60

watt lamp requires 0.272 A of current at 220 volts. If a 40 watt

lamp and a 60 watt lamp are connected in series with a 220 volt

line, how many amperes of current will flow through each lamp?​

Answer 1

Answer

Lamp A

power of lamp, p1 = 40W

amount of current required by the lamp, l1= 0.182A

voltage of the supply, V= 220V

Lamp B

power of bulb, p2= 60W

amount of current required by the lamp, l2= 0.272A

voltage of the supply, V= 220V

resistance of the lamp A, R1= V/l1 = 220/0.182= 1208.8 Ω

resistance of the lamp B, R2= V/l2= 220/0.272= 808.8 Ω

equivalent resistance when the two lamps are connected in series, R= R1+R2

=1208.8+808.8

=2017.6 Ω

current through each lamp when, connected to a 220V line is given by,

l= V/R=220/2017.6=0.109A