in a household , an electric bulb of 100W is used for 5 hours and an electric heater of 1000 watts for every day . calculate the cost of using bulb and the heater for 30 days if the cost of one unit of electrical energy is 2 rupees
Energy = Power x Time
Energy consumed by the bulb in one day = 100W x 5 hr = 500 Wh = 0.5 kWh
Energy consumed by the heater in one day= 1000 W x 1 hr = 1kWh (you have not given time,suppose it is 1hour)
Total energy consumed in one month(30 days) = (0.5 + 1) x 30 = 45 kWh
Cost of one unit = Rs. 2
Cost of 45 units =2 x 45= Rs. 90