Question

An electric heater of power 3kW is used for 10h.How much energy does it consume?Express your answer in (i) kWh, (ii)jouke

Answer 1

Power = 3kWh
Time= 3hr
Energy = kWh
=3 × 10
= 30 kWh

Answer 2

Power = 3 kW = 3000 W

Time = 10 h = 36000 s

${ \pink{ \bf{ P=E/T }}}$

${ \pink{ \bf{ E=P×T }}}$

E=3000×36000

E = 108000000J

${ \pink{ \bf{ In\: Joule \: = 1.08×10⁸J }}}$

1kWh = 3600000J

${ \pink{ \bf{ So, }}}$

108000000/3600000

${ \pink{ \bf{ In \: kWh \: =30kWh \: Ans }}}$