Practice question · Multiple choice
A fridge cools its contents while making the kitchen warmer overall. Why does that not violate the second law?
Hints
- Ask what the fridge does with the heat it removes, and where the motor's energy goes.
- Which system does the second law constrain: the interior, or the interior plus the kitchen?
Show the answer
B. Because the fridge is not isolated and dumps more heat than it removes
Why
Local order is always purchasable by exporting more disorder elsewhere, the fridge pays with work and dumps the total out of the back. The law constrains the whole, which is also how a living organism maintains itself, and why leaving the fridge door open warms the room.
Practise Thermodynamics and Statistical Ideas
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