Question

Find the energy in kwh consumed in 10 hours by a machine of power 500 w

Answer 1

Time:-10hrs

Power:-500 watt =500/1000=0.5kilowatt

Hence,

Energy consumed= power * time

E= 0.5*10

E=5kwh

Answer 2

Given:

• Power of machine = 500 Watt
• Time for which it operated = 10 hours.

To find:

• Energy consumed in kWh ?

Calculation:

Power is defined as the rate of consumption of energy (or the rate of doing work). So, we can say :

$Power = \dfrac{energy}{time}$

$\implies energy =Power \times time$

$\implies energy = \dfrac{500}{1000} \times 10$

$\implies energy =0.5\times 10$

$\implies energy =5 \: kW \: hr$

• Since 1 kW hr is considered as 1 unit of energy, we can also say :

$\implies energy =5 \:units$

So, net energy consumed is 5 kW hr or 5 units.