Question

in a house 4 bulbs of 50 watt each are used for 5 hours a day and two 70 watt fan each fan use 10 hours a day calculate the unit consumed in a month of 30 days???

Answer 1

Hi there !!

Power = Energy/Time

Energy = Power × Time

1kWh = 1 unit
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Energy consumed by bulb

Power = 50 Watt = 0.05 kW

Time = 5 hrs

Energy consumed by 1 bulb = 0.05 × 5

Energy consumed by 4 bulbs = 0.05 × 5 × 4
= 1 kWh
= 1 unit

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Energy consumed by fans :-

Power = 70 W = 0.07 kW

Time = 10 hrs

Energy consumed by 1 fan = 0.07 × 10

Energy consumed by 2 fans = 0.07 × 10 × 2
= 1.4 kWh
= 1.4 units


Total energy consumed = Energy consumed by 4 bulbs+Energy consumed by 2 fans × 30 days

= 1 + 1.4 × 30
= 2.4× 30
= 72 units

Answer 2

Given:

Power consumed by each bulb=50w=50/1000=0.05kW
Time=5hrs
energy consumed by bulb=E=P*t=0.05x5
energy consumed by 4 bulbs=4x5x0.05=1kWH
Energy consumed by fan:Power =70W=70/1000=0.07kW
Time=10hrs
Energy consumed by one fan=0.07x10=0.7kWH
energy consumed by 2 fans=2x0.7=1.4kWH
Total enrgy consumed=Energy consumed by bulb+energy consumed by fan
=1+1.4=2.4
Total energy consumption for 1 month=2.4 x30=72 units