Advertisements
Advertisements
प्रश्न
Find the energy in joules consumed in 10 hours by four devices of power 500 W each.
Advertisements
उत्तर
The power of four devices = 4 × 500 W
= 2000 W
Time = 10 hours
Therefore,
The energy consumed = power × time
= 2000 × 10 Wh
= 20000 Wh
= 20 kWh
= 20 units. ...[1 unit = 1 kWh]
APPEARS IN
संबंधित प्रश्न
What is power?
A lamp consumes 1000 J of electrical energy in 10 s. What is its power?
What is the work done by the force of gravity on a satellite moving round the earth? Justify your answer.
An electric heater is rated 1500 W. How much energy does it use in 10 hours?
Define kilowatt-hour.
A trolley is pushed along a road with a force of 400 N through a distance of 60 m in 1 minute. Calculate the power developed.
The power output of an engine is 3kW. How much work does the engine do in 20 s?
In an experiment to measure his power, a student records the time taken by him in running up a flight of steps on a staircase. Use the following data to calculate the power of the student :
Number of steps = 28
Height of each step = 20 cm
Time taken = 5.4 s
Mass of student = 55 kg
Acceleration = 9.8 m s−2
due to gravity
Which one of the following statements about power stations is not true?
How is the power related to the speed at which a body can be lifted? How many kilograms will a man working at the power of 100 W, be able to lift at a constant speed of 1 m s–1 vertically? (g = 10 m s–2)
