Question

An electric heater of power 3kw is used for 10h. How much energy does it consumes? Express your answer in kWh and joule

Answer 1

energy=3kw×10h=30kwh,energy=30×3.6×10^6=1.08×10^8

Answer 2

Power=3kw
Time=10h
Electric Energy=Electric power×Time
=3kw×10h
=30kwh...... (ans part 1)

As we know 1kwh=1000kwh
therefore = (1000w)×(60×60s)
=3.6×10^6J......... (ans part 2)