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संबंधित प्रश्न
An electron emitter must have _____________ work function and ___________ melting point.
A coolie is moving on a road with a luggage on his head. Does he perform work against the force of gravity? Give reason for your answer.
A machine raises a load of 750 N through a height of 16 m in 5 s. calculate:
- energy spent by machine,
- power at which the machine works.
Name the forms of energy which a wound-up watch spring possesses.
State two disadvantages of producing hydroelectricity.
State the energy transformation on the following:
Electricity is obtained from solar energy.
Define 1 joule of work.
What are the units of (a) work, and (b) energy?
Ravi applied a force of 10 N and moved a book 30 cm in the direction of the force. How much was the work done by Ravi?
Draw a neat labeled diagram to show the direction of two forces acting on a body to produce rotation in it. Also mark the point about which rotation takes place.
What is the SI unit of work?
Complete the following sentences:
Kilowatt is the unit of ....... and kWh is the unit of
Fill in the boxe to show the corresponding energy transformation.
In the following case write yes, if the work is being done and no if no work is being done.
A boy climbing up a staircase.
A girl of mass 40 kg runs a height of 80 stairs, each 25 cm high with a load of 20 kg on her head in 25 sec. If g is 10 m/s2, find:
(i) Gravitational force acting on the girl.
(ii) Work done by her.
(iii) Useful work done by her.
(iv) Her power in watt.
A bucketful of water is to be drawn from a well ______ will be done when a ______ is applied to do this because there will be a ______ of water.
(displacement, work, force)
