Calculate the current through a 60 W lamp rated for 250 V. If the line

1.	Calculate the current through a 60 W lamp rated for 250 V. If the line voltage falls to 200 V, how is the power consumed by the bulb affected?
Answer» Given, Power, p = 60 w Voltage, v = 250 v As power, P = VI I = 60/250 = 0.24 A Resistance of bulb R = V²/p = 250²/60 = 1041.6 Ω Now if voltage falls to 200 v, power consumes will be p = v²/R = 200²/1041.6 = 38.4 W

Calculate the current through a 60 W lamp rated for 250 V. If the line voltage falls to 200 V, how is the power consumed by the bulb affected?

Answer»

Given,

Power, p = 60 w

Voltage, v = 250 v

As power, P = VI

I = 60/250 = 0.24 A

Resistance of bulb R = V²/p = 250²/60 = 1041.6 Ω

Now if voltage falls to 200 v, power consumes will be

p = v²/R = 200²/1041.6 = 38.4 W