MHT-CET Physics Crash Course “Refrigerator” Class 12

“Refrigerator” MHT-CET Class 12 Physics Crash Course | Chapter Thermodynamics

In this session G.S. Khairnar discussed the theory and MCQ’s of “Refrigerator”. The session will be useful for all the aspirants of MHT-CET 2022. The session will be in Marathi and English.

Refrigerator:-

Hello dear students, in previous article we have learnt about the concept of heat engine. Heat engine uses heat to perform the mechanical work. The part of heat is used by to perform work and remaining part gets exhausted. The same principal is used in refrigerator also but in opposite direction.

Let’s learn the concept heat engine….!

The device which does the mechanical work for cooling the substance/ system is known as refrigerator and the process is called as refrigeration.

Refrigerator absorbs the heat from the system and transferred it to surrounding. Working substance consists of compressor, expansion valve and a closed tube which has refrigerant material like fluorinated hydrocarbon. Figure below shows the block diagram of working of refrigerator.

It consists of mainly three parts i.e. cold reservoir, working substance (compressor, expansion valve and a closed tube) and hot reservoir. The working process of refrigerator can be studied as follows.

  1. Heat is extracted from the cold reservoir and sends to the expansion nozzle through valve. It passes through the valve at low pressure and cools down.
  2. This process is adiabatic, so no exchange of heat is takes place during this.
  3. This cool gas gets contacted with thermal compartment of refrigerator and heats up.
  4. Heated gas is now sent to compressor. Compressor does the most of the work in the process, compresses the gas and converts it in to liquid again.
  5. The hot liquid is then passes through the coil outside fridge and then sends the heat to surrounding.

Performance of refrigerator:-