Question

There are 5 rooms in a house.Each room has 100W bulb and a 40W tubelight.If every day the bulb is use for 1hour and tubelight is use for 5hours in each room,then what will the cost of total electric energy consumed in 30days when one unit costs Rs.2.5

Answer 1

1 Unit is the household unit of electricity.1 unit is equal to 1 KWH which is equal to 1000 watts of power every hour.

Power consumed by bulb=100W=0.1KW

Power consumed by tube=40W=0.04KW

Units of power consumed by bulb=0.1KW *1=0.1

Units of power consumed by tube=0.04*5=0.2

Units of power consumed by 5 bulbs=0.1*5=0.5

Units of power consumed by 5 tubes=0.2*5=1

Total units of power consumed by bulbs in 30 days=0.5*30=15

Total units of power consumed by tubes in 30 days=1*30=30

Total cost of energy consumed by bulbs=15*2.5
=Rs 37.5

Total cost of energy consumed by tubes =30*2.5
=Rs 75

Overall cost
=Rs 37.5+ Rs 75
=Rs 112.5