AIIMS 2002
- Exam
- AIIMS
- Year
- 2002
- Subject
- Chemistry
- Chapter
- Thermodynamics (C)
AIIMS 2002 · Chemistry · Thermodynamics (C)
Assertion : During an adiabatic process, heat energy is not...
Assertion : During an adiabatic process, heat energy is not exchanged between system and its surroundings.
Reason : The temperature of a gas increases when it undergoes an adiabatic expansion.
Options
- AIf both the assertion and reason are true and reason is a correct explanation of the assertion.
- BIf both assertion and reason are true but assertion is not a correct explanation of the assertion.
- CIf the assertion is true but the reason is false.
- DIf both assertion and reason are false.
Correct answer
C. If the assertion is true but the reason is false.
Step-by-step solution
In adiabatic process, no heat enters or leaves the system. The system is completely insulated from its surroundings. From first law of thermodynamics, change in internal energy,
\Delta E=q-W=0-W=-W .
Since the work is done at the expense of internal energy, therefore internal energy of the system decreases and hence temperature of the gas falls.