(a) Define 1 watt.
(b) State the commercial unit of electric energy. Express it in terms of SI unit of energy.
(c) An electric refrigerator rated as 750 W operates 8 hours per day. What is the cost of the energy to operate it for a month of June at Rs. 2.50 per kWh?
s♡
Answers
Explanation:
(a) A body is said to have power of 1 watt if it does work at the rate of 1 joule in 1 s. Watt is the SI unit of power. Other units of power include ergs per second, horsepower, metric horsepower or cheval vapeur (CV)), and foot-pounds per minute. The unit Watt is named after the scientist James Watt.
(b) The commercial unit of electric energy is kilowatt hour (kWh), commonly known as 'unit'. One kilowatt hour is the energy consumed when 1000 watt of power is used for 1 hour. = 3.6 × 106 joule (J) (where joule 'J' is the S.I unit of energy.)
(c) Power of the refrigerator = 750 W. Operates for 8 hours each day. Cost per kWh = Rs. 2.50.
PLEASE MARK ME AS BRAINALIST ❤️
Answer:
- 1 watt is the power of an appliances which consumes energy at the rate of 1 joule per second
- The commercial unit of electric energy is kilowatt hour (kWh), commonly known as 'unit'. One kilowatt hour is the energy consumed when 1000 watt of power is used for 1 hour. = 3.6 × 106 joule (J) (where joule 'J' is the S.I unit of energy.
Power = P = 750 W = 750/1000 kW(1 kW = 1000 W), (1 W = 1/1000 kW)Time = t = 8 hrsEnergy = P*t = 750/1000*8 = 0.75*8 = 6 JEnergy consumption in one day = 6 JEnergy consumption in the month of June = 6*30 = 180 JTotal cost = monthly consumption*rate = 180*2.50= Rs 450The answer is Rs 450