Types of Systems in Thermodynamics

In thermodynamics, a system refers to the part of the universe under study. Based on interaction with surroundings, systems are classified into three main types. Types of Systems in Thermodynamics

Open System

An open system can exchange both matter and energy with its surroundings.

• Example: A boiling pot of water without a lid.
• Heat can enter or leave; steam (matter) can escape.

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Closed System

A closed system can exchange energy (heat/work) but not matter with its surroundings.

• Example: Water in a sealed, heated container.
• Energy crosses boundaries; matter stays constant.

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Isolated System

An isolated system cannot exchange either matter or energy with its surroundings.

• Example: Perfectly insulated thermos flask.
• No heat, work, or matter transfer occurs.

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Summary Table

System Type	Matter Exchange	Energy Exchange	Example
Open System	Yes	Yes	Boiling pot of water without lid
Closed System	No	Yes	Sealed heated container
Isolated System	No	No	Perfectly insulated thermos flask

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Quiz – Types of Systems

1. Which type of system allows exchange of both matter and energy?
   a) Open system
   b) Closed system
   c) Isolated system
   d) None
   Answer: a) Open system
   Explanation: Open systems exchange matter and energy freely.
2. A sealed container where heat can flow but matter cannot is:
   a) Open
   b) Closed
   c) Isolated
   
   Answer: b) Closed system
   Explanation: Closed systems allow energy exchange but not matter.
3. Which system exchanges neither matter nor energy?
   a) Open
   b) Closed
   c) Isolated
   
   Answer: c) Isolated system
   Explanation: Isolated systems are completely cut off from surroundings.
4. Example of isolated system:
   a) Boiling pot
   b) Thermos flask
   c) Car engine
   
   Answer: b) Thermos flask
   Explanation: Thermos prevents both energy and matter exchange.

Frequently Asked Questions

Q1. What are the 3 types of systems in thermodynamics?

A: Open, Closed, and Isolated systems based on energy and matter exchange.

Q2. What type of system is a refrigerator?

A: A refrigerator behaves like a closed system — energy is exchanged, but matter is not.

Q3. What is the difference between closed and isolated systems?

A: A closed system exchanges only energy, while an isolated system exchanges neither energy nor matter. Up Next: State and Properties of Matter | Learn more on Wikipedia