ENERGY CHANGES IN A SYSTEM

 As per the law of conservation of energy, Energy can neither be created nor be destroyed, but it can transfer from one form to another.

There are different forms of energy such as electrical energy, mechanical energy, chemical energy, Kinetic energy, potentials energy etc.. If there is change in system or surroundings one form of energy will be converted to other form, but the total energy of the system remains the same.

Let discuss some examples from our daily life where energy change happens according to the law of conservation of energy. 

1. wind mill - wind is the movement of air. All the moving objects possess kinetic energy. So wind pass through wind mill that kinetic energy is converted to mechanical energy and wind mill start moving. When windmill moves electric current is produced, that means mechanical energy is converted to electrical energy 
2. Electric fan - when fan is switched on Electric circuits will passes through the circuit and it start rotating. Here electrical energy is converted to mechanical energy 
3. Electric bulb - Electric bulb when switched on electrical energy is converted light and heat energy 
4. Car - Fuel used in car burns and produce energy for car to move. when fuel burns chemical energy is converted to heat energy.  in car engine, this heat energy produced is converted to mechanical energy