Question

Find the energy in kW h consumed in 10 hours by four devices of power 500 W each.

Answer 1

Energy consumed by an electric device can be obtained with the help of the expression for power,

Where,

Power rating of the device, P = 500 W = 0.50 kW

Time for which the device runs, T = 10 h

Work done = Energy consumed by the device

Therefore, energy consumed = Power × Time

= 0.50 × 10 = 5 kWh

Hence, the energy consumed by four equal rating devices in 10 h will be 4 × 5 kWh = 20 kWh = 20 Units.