Question

An electric bulb of resistance 200ohms draws a current of 1A. Calculate the power of the bulb and the energy consumed in kWh if it is burnt for 5h

Answer 1

Resistance = 200ohms
Current = 1
Voltage = 1 x 200 = 200 volts
Power = 200 x 200 ÷ 200
= 200 watts
Power consumed when bulb is lit for 5hrs = 200 x 5 = 1000 Watt hour
1000 Watt = 1kwh
So power consumed = 1kwh