An electric refrigerator rated 500 W operates 24 hours/day. What is the cost of the energy to operate it for 20 days at Rs.2.00 per kWh?

An electric heater of 1000W is used for 2 hours a day. What is the cost of using it for a month of 28 days, if 1 unit costs is 3.00 ?

An electrical appliance of 1000 W is used 6 hours/day. What is the electricity bill of the appliance in one day it the rate charged by electricity board is Rs.4/unit?

An electric bulb of 60 W is used for 6 hours per day. Calculate the units of energy consumed in one day by the bulb.

An electic room heater is rated at 2 kW. Calculate the cost of using it for 2 hours daily for the month of september, if each unit costs Rs. 4.00

A household uses the following electric appliance: Refrigerator of rating 400 W for 10 hours each day , find the energy consumed.

An electric bulb is rated 220V and 100 W. what is its resistance? Five such bulbs burn for 4 hours. What is the electrical energy consumed? Calculate the cost if the rate is 50 paise per unit.

A family pays 1000 for electricity on an average in those months in which it does not use a water heater. In the months in which it uses a water heater, the average electricity bill is 1240. The cost of using the water heater is ? 8.00 per hour. Find the average number of hours the water heater is used in a day.

A container opened from the top and made up of a metal sheet, is in the form of a frustum of a cone of height 16 cm with radii of its lower and upper end as 8 cm and 20 cm, respectively. Find the cost of made which can completely fill the container, at the rate of Rs 20 per litre. Also find the cost of metal shape used to make the container, if it costs Rs 8 per 16cm^(2) . (Take pi=3.14 )