Energy


 
 
Concept Explanation
 

Energy

Energy:

The word ‘energy’ is used in many contexts, just like the word ‘work’ is. We hear people talk of a person’s energy, energy-giving tonics and drinks, solar energy, nuclear energy, energy from petrol, and so on. Energy is the ability to do work. The object which does the work, losses energy and the object on which work is done, gains energy.

The SI unit of energy is same as that of work i.e. Joule (J).

1 Joule of energy is required to do 1 J of work. Larger unit of energy is KJ.

1KJ = 10^3J.

Work done against a force is therefore stored as energy:

.... (More Text Available, Login?)
Sample Questions
(More Questions for each concept available in Login)
Question : 1

Column I shows some devices and column II shows transformation of energy for which they are used. Then match the following.

Column IColumn II
(A) Electric motor(p) Electrical energy to heat energy
(B) Engine on an automobile(q) Electrical energy to mechanical energy.
(C) Electric heater(r) Light energy to electrical energy
(D) Photocell(s) Heat energy to mechanical energy.

 

Right Option : B
View Explanation
Explanation
Question : 2

Identify the unit of  energy ____________.

Right Option : D
View Explanation
Explanation
Question : 3

Identify  the kind of energy possessed by a running athlete.____________________.

Right Option : B
View Explanation
Explanation
 
 


Students / Parents Reviews [20]