Question

Find the energy consumed by the electric appliances in a month. Also find the bill of the month if an unit costs AED 3.50.
a) A TV of rating of 2760 W working 4.5 hrs in a day.
b) 5 fans of rating 850 W for a time of 9.5 hrs in a day.
c) 3 lamp of power 25 W working 11.5 hrs in a day.

Answer 1

Given:  

TV Power Consumption: 2760 W

Number of Hours TV works: 4.5 hours

Fan Power consumption: 850 W

Number of Hours fan works:  9.5 hours

Number of Fans:  5

Lamp Power consumption: 25 W

Number of Lamps: 3

Number of hours lamp works: 11.5

Cost per unit: 3.50 AED

To Find:

The energy consumed by the electric appliances in a month and the bill of the month

Solution:

Now, this is a very big problem hence we will break it down into parts. FIrstly we figure out the formula for calculating the energy consumed.

The formula is:

Power consumption of an appliance – Wattage X Operational hours

Now we figure out the wattage television consumes but firstly we need it to figure it out for a month so we need to find out how many hours the TV is used in the month which :

number of hours in a day x 30

4.5x30 = 135 hours per month

Now the consumption:

2760x 135= 373,275 Watts

Converted to kilowatts approximately = 373Kw

Now we figure out how much the fans consume:

Following the same formula:

9.5x 30=  285 hours per month

Now the consumption:

850x 285= 242,250 watts

Converted to kilowatts approximately = 242Kw

But we have 5 fans hence and we found out for 1 fan, now we multiply the answer by 5

242Kw x5= 1210 Kw for 5 fans

Now for the lamps following the same formula:

11.5 x 30= 345 hours per month

Now the consumption:

25x 345= 8625 watts

Converted to killowats approximately = 9kw

But we have 3 lamps hence we multiply it by 3:

9x3= 27kw per month for 3 lamps

Solution for part a)

• Tv uses 373Kw per month
• 5 fans uses 1210 Kw per month
• 3 Lamps uses 27Kw per month

The total bill for the following can be calculated by this formula:

Electricity Bill For Using An Appliance = Power Consumption X Electricity Tariff

So we add all the power units is comes up to:

1610 Kw

Adding it to the formula;

1610 x 3.50= 5635 AED

the bill is 5635 AED

Solution for part b)

The bill is 5635 AED

Solution:

• Tv uses 373Kw per month
• 5 fans use 1210Kw per month
• 3 Lamps uses 27Kw per month
• The bill is 5635 AED