The total electric energy consumed by an individual (especially houses) measured in kilowatt-hour is called electric power consumption. All the power companies install a meter in their customer's house so that they can charge according to the electric consumption. Those installed meters measure electricity on kilowatt-hour (KWH). In normal terms, we say 1 unit for 1 KWH. It is actually the amount of power used for a certain period of time. For the easy purpose, we say an electrical appliance of 1000W consuming power for one hour will consume 1KWH i.e. 1KWH = 1KW x 1hr.
Power Consumption = Power consumed by appliance x no of appliance x time operating
= P (in KW) x N x T (in hour)
Amount to pay = power consumption x price per unit
So, to calculate total power consumption of a home, we need to know the power of each equipment, number of equipment and time they run. Since all the appliances are not run at the same time and same period of time it is better to calculate power consumed by each appliance and add all at last.
If a home has 10 tube lights of 30W that run for 4 hours daily, 5 television of 200W running for 3 hours daily, 2 irons 1000W 1 hour weekly. Calculate total amount to be paid if the cost per unit is Rs. 7.
Power consumed by tube lights in one day = 10 x 301000 x 4 = 65 KW Power consumed by tube lights in one month = 65 x 30 = 36 KW
Power consumed by television in one day = 5 x 2001000 x 3 = 3 KW Power consumed by television in one month = 3 x 30 = 90 KW
Power consumed by iron in one week = 2 x 10001000 x 1 = 2KW Power consumed by iron in one month = 2 x 4(one month has 4 weeks) = 8 KW
Total power consumption in one month = 36 + 90 + 8 = 134KW Total amount to be paid = total power consumption x price per unit= 134 x 7 = Rs. 938
1 kwhr = 1 unit
1 kwhr = 1000 watt hour
1 kwhr = 1000 watt × 3600 sec
1 kwhr = 3600000 joules
1 kwhr = 3.6 × 106 joules
The electricity authority charged the cost of electricity per unit is Rs. 6.50. If in a house 4 bulb of 100 watt glow for 5 hours a day. Find the cost of electricity for 1 month.
Power of bulb = 100 watt
Numbers of bulb = 4
Hence, the consumption per day = PNT
= 100 × 4 × 5
= 2000 wh
Now, the consumption for one month = 30 × 2000 wh
= 60 kwh
= 60 unit
The total cost of electricity = unit consumed × per unit cost
= 60 × 5.50
= Rs. 390
© 2019-20 Kullabs. All Rights Reserved.