25. Which of the following is a statement or a consequence of 2nd law of thermal dynamics?
(A) The efficiency of any heat engine operates between two heat reservoir is less or equal to the Carnot engine.
(B) Heat can never pass from a colder to a warmer body without some other changes occurring at the same time.
(C)Entropy of an object always increases when it is in contact with a heat reservoir.
(D) Isolated perpetual motion machine is not possible.
(E) The entropy of a thermal system going through a cyclic process always increases or stays the same after a full cycle.

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統計： A(3), B(2), C(1), D(3), E(3) #2740303

詳解 (共 1 筆)

#7431019
所以看到熱力學第二定律
要想到主要在講甚麼(熱現象具有方向性)
1.熱會自然從高溫到低溫
2.不可能把吸收的熱百分之百轉換成功
3.孤立系統的總商不會減少
要想到卡諾定理
任兩個熱庫之間運作的熱機
不可能超過卡諾循環之熱機
熱不會自然從冷庫到熱庫
而熱力學第二定律講的是
總商不減少
不過各別的商可以增加
對於系統而言的商
總商是不變的
不過熱力學第二定律講的是宇宙的總商
包含系統的商和環境的商
所以總概括起來是大於等於0
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