Advertisements
Advertisements
प्रश्न
What is power?
उत्तर
Power is the rate of doing work or the rate of transfer of energy. If W is the amount of work done in time t, then power is given by the expression,
The rate of doing work or energy conversion rate is called power.
Power = `"Work" /"time"`
or P = `W/t`
Where, P = Power
w = Work
t = Time
APPEARS IN
संबंधित प्रश्न
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?
Find the energy in joules consumed in 10 hours by four devices of power 500 W each.
Calculate the work done by the brakes of a car of mass 1000 kg when its speed is reduced from 20 m/s to 10 m/s?
A body of mass 100 kg is lifted up by 10 m. Find :
(i) the amount of work done
(ii) potential energy of the body at that height (value of g = 10 m/s2)
Define kilowatt-hour.
A body does 1200 joules of work in 2 minutes. Calculate its power.
In loading a truck, a man lifts boxes of 100 N each through a height of 1.5 m.
If the man lifts 4 boxes per minute, at what power is he working?
(g = 10 m s−2)
Which one of the following statements about power stations is not true?
