Question

In a house there are 4 lamps 20 watt 2 lamps 10watt 3lamps 40watt are used in 5 houses everyday. If the electric company charge 0.092 per kwh then the cost of using electric energy during 1 month is

Answer 1

Answer:

(1) 4 lamps each of 20 watt = 4×20= 80 watts

(2) 2 lamps each of 10 watt = 2×10= 20 watts

(3) 3 lamps each of 40 watt = 3×40= 120 watts

(4) total watts, P = 80+20+120= 200 watts

(5) Total energy E= Power × Time = 200×5=1000 Watt-hour or 1 kWH

(6) one month = 30 days× 5 hours =150 hours

power consumption in a month = 150 kWH

(7)Cost of energy = 150 ×0.092 =Rs. 13.80

Answer 2

Answer:

4 lamps of 20w = 80w

2 lamps of 10w = 20w

3 lamps of 40w = 120w

Total power:- 80w+20w+120w

Total time 30×5=150hr

Explanation:

Electrical energy consumed during one month(30days) = power×time

= 220×150

= 33000Whr

In KWHr=33000÷1000=33kwhr

1 kwhr=0.092₹

33kwhr:- 33×0.092= ₹ 3.036

Therefore ,cost of using electrical energy during one month(30days) :- ₹ 3.036