Advertisements
Advertisements
प्रश्न
Define power. Give the SI unit of power.
उत्तर
Power is defined as rate of doing work. It is also defined as rate at which energy is consumed. SI unit of power is watt.
APPEARS IN
संबंधित प्रश्न
A lamp consumes 1000 J of electrical energy in 10 s. What is its power?
A battery lights a bulb. Describe the energy changes involved in the process.
A person holds a bundle of hay over his head for 30 minutes and gets tired. Has he done some work or not? Justify your answer.
Find the energy in joules consumed in 10 hours by four devices of power 500 W each.
Define kilowatt-hour.
A body does 1200 joules of work in 2 minutes. Calculate its power.
Fill in the blank with suitable word :
Power is the rate of doing ___________.
An electric heater uses 600 kJ of electrical energy in 5 minutes. Calculate its power rating.
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)
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)