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A 100 watt bulb is used for 5 hours dail...

A 100 watt bulb is used for 5 hours daily and four 60 watt bulbs are used for 5 hours daily. Calculate the energy consumed (in kWh) in the month of January.

Text Solution

Verified by Experts

100 w = 100 joules per second
1 watt hours = 3600 joules
The electric bulb is lighted for 5 hours daily,
`:.100Wxx5=500` watt hours
500 watt hours = 1800000 joules
1 kWh = 3600000 joules
Units consumed per day `=(1800000)/(3600000)=0.5` units
Untis consumed in month `=0.5xx31=15.5` units .. . . . (1)
Now, Sum of power of four 60 watt bulbs = 240 W
240 `Wxx5` hours = 1200 watt hours
1200 watt hours = 4320000 joules
Energy consumed per day `= (4320000)/(3600000)=1.2` units
Energy consumed in a month `=1.2xx31=37.2` units . . . . (2)
Total energy consumed in a month `=15.5+37.2`
`" "=52.7` units
1 unit = 1 kWh
The energy consumed in the month of January `=52.7` kWh
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