Question

27) A 2 kW heater, a 400 W TV and three 150 w lamps are all switched on from 6 am to
p.m. What is the total cost at Rs. 8.50 per kWh ?​

Answer 1

Answer:

For heater,

Power = 2000 W

Time switched on = 12 hours

Units consumed = Power*Time/1000

= 2000*12/1000

= 24 kWh

For TV,

Power = 400 W

Time switched on = 12 hours

Units consumed = 400*12/1000

= 4.8 kWh

For Lamps,

Power = 150*3 = 450 W

Time consumed = 12 hours

Units consumed = 450*12/1000

= 5.4 kWh

Total consumed units in a day = ( 5.4+4.8+24 ) kWh

= 34.2 kWh

Cost for a day = (34.2*8.5)

= Rs. 290.7

Cost for a month = (290.7*30)

= Rs. 8721

I hope that helps.