Question

A house has 3 tube lights, two fans and a Television. Each tube light draws 40W. The fan draws 80W and the Television draws 60W. On the average, all the tube lights are kept on for five hours, two fans for 12 hours and the television for five hours every day. Find the cost of electric energy used in 30 days at the rate
of Rs. 3.00 per Kwh. (AS,)

Answer 1

Dear Student,
Given,
Number of tube lights of power 40 W = 3
Number of fans of power 80 W= 2
Number of televisions of power 60 W = 1

Operating hours per day:
Each tube light = 5 h
Total operating hours of 3 tube lights = 15 h
Energy consumed by the tube lights = $40W\times 15h=600Wh$

Each fans = 12 h
Total operating hours of 2 fans = 24 h
Energy consumed by the fans = $80W\times 24h=1920Wh$

The television = 5 h
Energy consumed by the television = $60W\times 5h=300Wh$

Total energy consumed per day = $600+1920+300=2820Wh=2.82kWh$
So, in 30 days total energy consumption = $30\times 2.82kWh=11.52kWh$
Electricity charges = Rs 3.00 per kWh
So, cost of electrical energy used in 30 days = $11.52\times 3=Rs.34.56$
Regards