Question

What is the commercial unit of energy? Convert into Joules. What is the other name of these commercial units?

Answer 1

Hint A kilowatt is equal to a thousand watt of power. Commercial units of energy are those which are used in industrial functions or consumption calculations. Joule is a standard unit and it is also an SI unit of energy.

Complete step by step answer
In our everyday life, the usage of energy is enormous. In addition, the Joule is quite a small unit of energy. In electrical terms, it is defined as the energy used when 1 ampere of current flows through a load for one second when a potential difference of 1 volt is applied across it.
Now let us investigate the energy usage in joules. The potential difference of electricity supplied into our homes is 240 V and 120 V depending on the country. Assuming a one ampere current is flowing through a home appliance connected for a day, the energy consumed by it is calculated as:
 $ \Rightarrow {\text{1A}} \times {\text{240V}} \times {\text{24hrs}} \times {\text{60}}\dfrac{{{\text{min}}}}{{hr}} \times 60\dfrac{s}{{\min }} = 20736000J $ . We see the enormous amount of energy consumed by this device in joules.
However, writing such units in commercial activities can look daunting, and in fact exhausting to write. Hence, a need for a much larger unit. The kilowatt hour is the unit employed for this purpose.
Converting 1 kWh to Joule is given as
 $ \Rightarrow 1KWh = 1kWh \times 1000\dfrac{W}{{kW}} \times 60\dfrac{{\min }}{{hr}} \times 60\dfrac{s}{{\min }} = {3.610^6}{\text{J}} $
Hence,
 $ \Rightarrow 1KWh = {3.610^6}{\text{J}} $
Another unit identical to the kWh is the kVAh (kiloVolts-Ampere-hour).
Hence, another name for kWh is the kVAh.

Note
In application, however, while the kilowatt hour is used for the exact (real) energy consumed by a device, the kilovolt ampere hour is used to calculate the total apparent energy consumed by the entire process. This includes energy lost in reactive elements.