Question

calculate the monthly bill for a heater of resistance 25 ohm which is used on 220 v mains such that its daily use in for 3 hours the cost of electricity electric energy is rupees 4.20 per unit

Answer 1

Explanation:

R=25ohm

V=220V

Power=V^2/R

so power=220×220/R

P=48400÷25

P=1936

so power=1936watt

We have to find it in kilo So 1936÷1000

1.936Kilowatthour(kwh) or 1.936unit

For 1Hour=1.936kwh

so for 3Hour in a day

so in 30days we have 28days there is 28×3=84hours

so for 84 hours or 28 day or in a mont the total unit consumed by heater=84×1.936=162.624kwh or unit

so amount will be 4.20×162.624

so the total amount consumed by heater if used 3 hrs. daily for a month=683.02rs