Energy Conversion

Energy conversion also termed as the energy transformation, is the process of changing one form of energy into another. Energy conversion occurs everywhere and every minute of the day. There are numerous forms of energy like thermal energy, electrical energy, nuclear energy, electromagnetic energy, mechanical energy, chemical energy, sound energy etc. On the other hand, the term Energy Transformation is used when energy changes forms from one form to another. Whether the energy is transferred or transformed, the total amount of energy doesn’t change and this is known as the Law of Conservation of Energy.

The Law of Energy Conversion

Energy Conversion

The diagram shows how different forms of energy can be converted to another form of energy
 

Thermodynamics is the study of how energy gets converted from one form to another. Details on how the laws of thermodynamics apply to the conversion of energy are given below.

The first law of thermodynamics states that

Energy can neither be created nor destroyed, it can only be transformed from one form to another.

This is also known as the law of conservation of energy or the law of energy conversion. There are various types and forms of energy. Some examples of everyday energy conversions are provided below.

Scenario
Energy conversions involved
Rubbing both hands together for warmth
Kinetic Energy to Thermal Energy
A falling object speeding up
Gravitational Potential Energy to Kinetic Energy
Using battery-powered torchlight
In the battery: Chemical to Electrical Energy
In the bulb: Electrical to Radiant Energy
In Geothermal Power Plant
Heat Energy to Electrical Energy
In Thermocouple
Heat Energy to Electrical Energy
In Hydroelectric Dams
Gravitational potential energy to Electric Energy
In Electric Generator
Kinetic energy / Mechanical work to Electric Energy
In Windmills
Wind Energy to Mechanical Energy or Electric Energy
In OTEC
Heat Energy to Electric Energy or Mechanical Energy
Using Microphone
Sound Energy to Electric Energy
Photosynthesis in Plants
Solar Energy to Chemical Energy
In Piezoelectrics
Strain to Electric Energy
In Electric lamp
Electric Energy to Heat and Light Energy
Burning of wood
Chemical energy to Heat and Light Energy
In Fuel cells
Chemical Energy to Electric Energy
In steam engine
The heat energy to Mechanical Energy
In Electric heater
Electric Energy to Heat

Examples of Energy Conversion

Some examples of sets of energy conversion in machines are explained below.

Coal-fired Power Plant

Coal-Fired Power Plant

In coal-fired powerplants, the chemical energy in the coal after a series of transformations, gets converted into electrical energy

The sets of energy transformation inside a coal-fired power plant are given in the points below.

  • During the process of combustion, the chemical energy in the coal gets converted into thermal energy.
  • Then through the heat exchanger, the thermal energy of the exhaust gases gets converted into thermal energy of steam.
  • After that in the turbine, the thermal energy of steam gets converted into mechanical energy.
  • Finally, with the help of a generator, the mechanical energy gets converted into electrical energy.

Conventional Automobile

The sets of energy transformation in a conventional automobile are given in the points below.

  • Due to combustion, the chemical energy in the fuel gets converted into kinetic energy of the expanded gas.
  • Then the kinetic energy of the expanding gas gets converted into linear piston movement.
  • Then the linear piston movement gets converted into rotary crankshaft movement.
  • The rotary movement of drive wheels gets converted into linear motion of the automobile.

Energy Transfer vs Energy Transformation vs Energy Conservation

What is Energy Transfer?

The movement of energy from one location to another.

What is Energy Transformation?

The process of the changing of the energy from one type to another.

What is Energy Conservation?

It means that the total amount of energy remains the same.

Practice Question

Using the following diagram answer the following questions. Neglect the effect of resistance forces.

Conservation of Energy

  1. What happens to the sum of gravitational potential and kinetic energies when the object moves from point A to point D across the surface?

  2. Answer: The total mechanical energy (i.e., the sum of the kinetic and potential energies) remains the same whenever there are no external or nonconservative forces (such as friction or air resistance) doing work.

  3. At what point will the object have a minimum gravitational potential energy?

  4. Answer: The gravitational potential energy depends on the height. The potential energy is minimum when the height is minimum. At point B, the object will have minimum gravitational potential energy.

  5. At which point in the diagram is the object’s kinetic energy lesser than the object’s kinetic energy at C?

  6. Answer: Since the total mechanical energy is conserved, kinetic energy will be greatest when the potential energy is smallest. Point B is the only point that is lower than point C. The reasoning would follow that point B is the point with the smallest PE, the greatest KE, and the greatest speed. Therefore, the object will have less kinetic energy at point C than at point B (only).

Stay tuned with BYJU’S to learn more interesting Physics topics like Ohm’s Law, Thermodynamics, Laws of Motion, etc.

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