Advertisements
Advertisements
प्रश्न
Differentiate between energy and power.
State the differences between energy and power.
Give two differences between power and energy.
Advertisements
उत्तर
| Energy | Power | |
| 1. | The energy of a body is its capacity to do work. | The power of a source is the energy spent by it in 1s. |
| 2. | Energy spent does not depend on time. | Power spent depends on the time in which energy is spent. |
| 3. | S.I unit of energy is the joule (J). | S.I unit of power is watt (W) |
APPEARS IN
संबंधित प्रश्न
A pair of bullocks exerts a force of 140 N on a plough. The field being ploughed is 15 m long. How much work is done in ploughing the length of the field?
An object thrown at a certain angle to the ground moves in a curved path and falls back to the ground. The initial and the final points of the path of the object lie on the same horizontal line. What is the work done by the force of gravity on the object?
Write the expression for work done by a force.
Name the forms of energy which a wound-up watch spring possesses.
A boy tries to push a truck parked on the roadside. The truck does not move at all. Another boy pushes a bicycle. The bicycle moves through a certain distance. In which case was the work done more : on the trick or on the bicycle? Give a reason to support your answer.
Each of the following statement describes a force acting. Which force is causing work to be done?
A 100 W electric lamp emits energy in the form of light at the rate 10 J per second. What percentage of electric energy does the lamp transform into light energy?
A bullet is of mass 'm' g and is moving with a velocity 'v' m/s. Find the kinetic energy of the bullet when
(a) The mass is doubled,
(b) The velocity is tripled.
Name the material commonly used for the manufacturing of solar cells.
A coolie is pushing a box weighing 1500 N up an inclined plane 7.5 m long on to a platform, 2.5 m above the ground.
(i) Calculate the mechanical advantage of the inclined plane. (ii) Calculate the effort applied by the coolie.
(iii) In actual practice, the coolie needs to apply more effort than what is calculated. Give one reason why you think the coolie needs to apply more effort.
