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प्रश्न
उत्तर
SI unit of power = watt
CGS unit of power = erg per second
1` W = 1 J s -1 = 107 erg s -1
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संबंधित प्रश्न
State the S.I. unit of work and define it.
Give reasons for the following A teacher moving around in the class is doing work but a child standing and reading a book is not doing any work.
A force of 30 N acts on a body and moves it through a distance of 5 m in the direction of force. Calculate the work done by the force.
A water pump raises 50 litres of water through a height of 25 m in 5 s. Calculate the power of the pump required.
(Take g = 10 N kg-1 and density of water = 1000 kg m-3)
Fill in the blank with suitable word :
Work is measured as a product of __________ and __________
Choose one or more correct alternatives.
Joule is the unit of ______.
- force
- work
- power
- energy
A man carrying a suitcase in his hand is walking horizontally. What is the work done against gravity?
On what factors does the work done by a force depend?
A weight lifted a load of 200 kgf to a height of 2.5 m in 5 s. calculate: (i) the work done, and (ii) the power developed by him. Take g= 10 N kg-1.
A body does 20 J of work in 10 s. What is its power?
State the energy changes which take place when An electric bulb glows when it is connected to a source of electric current.
State the energy changes which take place when A toy car with a wound spring moves on ground.
Give an example
Electrical energy changes of sound energy.
The weights of two bodies are 2.0 N and 2.0 kgf respectively what is the mass of each body?
Mention whether work is done or not in the following activity.
| S. No | Activity | Work done or not done |
| 1. | Pushing the door | |
| 2. | Holding a doll | |
| 3. | Sitting in a bus | |
| 4. | Pushing a wall | |
| 5. | Digging soil |
