Question

Commercial unit of electric energy is kilowatt hour$\left ({kWh} \right)$. Convert $1{\text {kWh}}$ into Joule.

Answer 1

Here, we have to define the commercial unit of electric energy and how the commercial unit of electric energy is different from domestic. And convert one kilowatt hour in joules. How an electrical device consumes one kilowatt energy for one hour in a commercial place i.e. in factories or other business sectors.

Complete step by step solution:
As we know, electrical energy is measured in kilowatt hour. The commercial unit of electrical energy is kilowatt hour $\left ({kWh} \right)$
The kilowatt-hour is a unit of energy equivalent to one kilowatt $1{\text {kWh}}$ of power expended for one hour $\left ({1h} \right)$ of time. It does not mean the number of kilowatts you are using per hour. It is simply a unit of measurement that equals the amount of energy you would use if you kept a $1000$ watt appliance running for an hour. So, if you switched a $100$ watt light bulb, it would take $10{\text {hours}}$ to rack up $1{\text {kWh}}$ of energy. The kilowatt-hour is not a standard unit in any formal system, but it is commonly used in electrical applications. $kWh$ is the unit of electrical energy, it is the same for both commercial as well as domestic. Commercial units are having different rates of charge and it is more than domestic unit rates. It is basically applied on power consumption in factories or other business sectors which consumes more electrical energy.

$1{\text {kWh}}$, can be converted to joule as
$1{\text {kWh}}$ $=$ $1{\text {kW}}$ $\times$ $1hour$
As we know that, $1kW = 1000{\text {W}}$
And $1hour = 3600{\text {sec}}$
$1{\text {kWh}} = 1000{\text {W}} \times 3600{\text {sec}}$
$1{\text {kWh}} = 3.6 \times {10^6} {\text {J}}$

Note: Here, the commercial unit of electric energy is kilowatt hour and $1{\text {kWh}} = 3.6 \times {10^6} {\text {J}}$. So, be careful while converting the kilowatt hour into joules. And the appliances working for an hour are $kWh$. It is measured in SI units i.e. joule.