4thSem: (2)To measure power of an appliance and calculate time for 1 kWh unit of electric energy consumption.

 Aim : To measure power of an appliance and calculate time for 1 kWh unit of electric energy consumption.

Diagram : 

Procedure:

To calculate the consumption of an electrical appliance in kWh, you have to take into account three factors:

the capacity of your electrical appliance, expressed in watt.
the number of hours that the appliance is in use in one day.
the number of days per year when the appliance is in use.

The calculation :

[number of  hours’ use] x [number of days’ use] x ([capacity of appliance expressed in watt] / 1,000) = number of kWh

The capacity should be divided by 1,000 to convert the number of watts into the number of kilowatts. This finally gives us the number of kWh (kilowatt hours).

Calculation for the energy consumption of a vacuum cleaner

In the table below we assume that

 the vacuum cleaner is used for two hours once a week.

hours / day	2 hours
days / year	52 days
Capacity of vacuum cleaner	2000 watts

Result : 

Annual energy consumption of vacuum cleaner is calculated as

208kWh

2 x 52 x(2,000 watts/1,000)=208 kWh.