Question 29:
(a) What is meant by “electric power” ? Write the formula for electric power in terms of potential difference and current.
(b) The diagram below shows a circuit containing a lamp L, a voltmeter and an ammeter. The voltmeter reading is 3 V and the ammeter reading is 0.5 A
(i) What is the resistance of the lamp ?
(ii) What is the power of the lamp ?
(c) Define kilowatt-hour. How many joules are there in one kilowatt-hour ?
(d) Calculate the cost of operating a heater of 500 W for 20 hours at the rate of ? ₹ 3.90 per unit.
Lakhmir Singh Physics Class 10
Answers
Answered by
7
Answer:
Explanation:
power is how much energy is transfered in a second
potential differenc is also called as voltage so
power= current*voltage
(b) Resistance=voltage/current
=3/0.5
=6 ohms
(ii) power= I*V
=3*.5
=1.5W
Answered by
8
Answer:
Electric power is the rate, per unit time, at which electrical energy is transferred by an electric circuit.
hope the definition helps:)
Similar questions