Practice question · Multiple choice
A gas in an insulated cylinder (no heat exchange) is compressed by pushing the piston in. What happens to the gas temperature?
Hints
- First law: . Here but you did work on the gas.
- "No heat" does not mean "no energy transfer", work is the other channel.
Show the answer
B. It rises: the work done becomes internal energy
Why
Adiabatic compression pumps energy in through work alone, so , and with it the temperature, must rise. A bicycle pump warming up, and a diesel engine igniting fuel with no spark plug, are both this line of the first law in action.
Practise First Law of Thermodynamics
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