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प्रश्न
What should be the characteristic of a source of energy?
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उत्तर
A good source of energy should have the following characteristics:
(i) It should do a large amount of work per unit mass or volume.
(ii) It should have a high calorific value.
(iii) It should be easily accessible over a long period of time.
(iv) It should be economical and easy to store and transport.
(v) It should be safe and convenient to use.
संबंधित प्रश्न
When do we say that work is done?
The S.I. unit of energy is .............
In which of the following cases, is work being done?
(i) A man pushing a wall.
(ii) a coolie standing with a load of 12 kgf on his head.
(iii) A boy climbing up a staircase.
A car is being driven by a force of 2.5 ✕ 1010 N. Travelling at a constant speed of 5 m/s, it takes 2 minutes to reach a certain place. Calculate the work done.
The work done by a force acting obliquely is given by the formula : W = F cos θ ✕ s. What will happen to the work done if angle θ between the direction of force and motion of the body is increased gradually? Will it increase, decrease or remain constant.
How is horse power related to the S. I. unit of power?
Look at the activity below. Reason out whether or not work is done in the light of your understanding of the term ‘work’.
Suma is swimming in a pond.
State whether work is done or not, by writing yes or no, in the following case:
A man pushes a wall.
