Question

An electric kettle of 2 kW is used for 2h. Calculate the energy consumed in 

1. kilowatt hour and
2. joules.

Answer 1

(i) Power, P = `"E"/"t"`

So, energy consumed, E = P × t = 2 × 2 = 4 kWh

(ii) Energy consumed, E = 4 kWh

= 4 × 1000 × 3600 J

= 1.44 × 10⁷ J