Question

an electronic heater of power 3kwh is used for 10h.how much energy does it consumed? express yours answer in (I)kwh(ii)joule

Answer 1

Given,
 Power = 3 kW
  time = 10 h

Therefore,
 electric energy = Electric power x Time
                         = 3 kW x 10 h = 30 kWh

As 1 kWh = 1000 Wh  = (1000 W) x (60 X 60s) = 3.6 x 10^6 J
Therefore,
 electric power = 30 kWh = 108 x 10^6 J = 1.08 x 10^8 J


i hope it will help you
regards

Answer 2

Power = 3 kW = 3000 W

Time = 10 h = 36000 s

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

${ \orange{ \bf{ E=P×T }}}$

E=3000×36000

E = 108000000J

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

1kWh = 3600000J

${ \orange{ \bf{ So, }}}$

108000000/3600000

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