Given below are two statements:
 Assertion (A): Reversible systems are difficult to find in the real world. Reason (R): Most processes are dissipative in nature.

 1 Both (A) and (R) are true and (R) is the correct explanation of (A). 2 Both (A) and (R) are true but (R) is not the correct explanation of (A). 3 (A) is true but (R) is false. 4 Both (A) and (R) are false.
Subtopic:  Second Law of Thermodynamics |
80%
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A sink, that is, the system where heat is rejected, is essential for the conversion of heat into work. From which law does the above inference follow?
1. Zeroth
2. First
3. Second
4. Third

Subtopic:  Second Law of Thermodynamics |
58%
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Consider a cycle followed by an engine (figure).

1 to 2 is isothermal,

Such a process does not exist, because:

 a. heat is completely converted to mechanical energy in such a process, which is not possible. b. In this process, mechanical energy is completely converted to heat, which is not possible. c. curves representing two adiabatic processes don’t intersect. d. curves representing an adiabatic process and an isothermal process don't intersect.

Choose the correct alternatives:
1. (a, b)
2. (a, c)
3. (b, c)
4. (c, d)

Subtopic:  First Law of Thermodynamics | Second Law of Thermodynamics |
55%
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Given below are two statements:
 Statement I: The efficiency of any thermodynamic engine can approach $$100\%$$ if friction and all dissipative processes are reduced. Statement II: The first law of thermodynamics is applicable only to non-living systems.
 1 Statement-I is incorrect and Statement-II is correct. 2 Both Statement-I and Statement-II are correct. 3 Both Statement-I and Statement-II are incorrect. 4 Statement-I is correct and Statement-II is incorrect.
Subtopic:  Second Law of Thermodynamics |
53%
From NCERT