Q134 / 160 · AP EAMCET 2020 (22 Sep Shift 2) · Physics

During phase change, entropy

A
remains constant
B
always increases
C
always decreases
Correct answer
D
may increase or decrease

Solution

The entropy of a system during phase change (phase transition) increases, if the phase transition is towards higher internal energy (e.g., during melting) and decreases if the phase transition is towards lower internal energy (e.g., during freezing). Therefore, during phase change, entropy of the system may increase or decrease.

Hence, the correct answer is option: 'D'.

Relevant Questions

If the ratio of the absolute temperature of the sink and source of a Carnot engine is changed from to , the efficiency of the engine changes23 May, 2024 (M)Heat Engine, Refrigerator and Second Law of Thermodynamics
The efficiency of a Carnot heat engine is and the temperature of its source is . Without changing the temperature of the source, if absolute22 May, 2024 (E)Heat Engine, Refrigerator and Second Law of Thermodynamics
In a Carnot engine, when the temperatures are and , its efficiency is and when the temperatures are and , its efficiency is . Then the value21 May, 2024 (M)Heat Engine, Refrigerator and Second Law of Thermodynamics
The efficiency of a Carnot engine found to increase from to on increasing the temperature ( ) of source alone through 100 K . The temperatur21 May, 2024 (E)Heat Engine, Refrigerator and Second Law of Thermodynamics
The efficiency of a Carnot cycle is . By lowering the temperature of sink by 65 K , it increases to . The initial and final temperature of t20 May, 2024 (M)Heat Engine, Refrigerator and Second Law of Thermodynamics
In a cold storage, ice melts at the rate of 2 kg per hour when the external temperature is . The minimum power output of the motor used to d20 May, 2024 (M)Heat Engine, Refrigerator and Second Law of Thermodynamics