Selected MCQ

Current Question
Which law defines entropy change in irreversible processes?
  • A. First law
  • B. Second law
  • C. Third law
  • D. Zeroth law
Correct Answer: B
Explanation:
Entropy increases in irreversible processes.
Related Question 1
The entropy change for a reversible process is given by:
  • A. (dS = \delta Q)
  • B. (dS = \delta Q/T)
  • C. (dS = TdQ)
  • D. (dS = Q/T^2)
Correct Answer: B
Explanation:
Entropy change equals heat transfer divided by temperature in reversible processes.
Related Question 2
Which constant defines thermal energy scale?
  • A. Planck constant
  • B. Boltzmann constant
  • C. Avogadro number
  • D. Gas constant
Correct Answer: B
Explanation:
(k_B) relates temperature to energy.
Related Question 3
Which process increases entropy most?
  • A. Freezing water
  • B. Mixing gases
  • C. Crystallization
  • D. Condensation
Correct Answer: B
Explanation:
Mixing increases randomness.
Related Question 4
Which system exchanges gases?
  • A. Digestive
  • B. Respiratory
  • C. Circulatory
  • D. Nervous
Correct Answer: B
Explanation:
Lungs exchange gases.
Related Question 5
Which gas exchange occurs in alveoli?
  • A. O₂ out, CO₂ in
  • B. CO₂ out, O₂ in
  • C. Both out
  • D. None
Correct Answer: B
Explanation:
Oxygen diffuses into blood, CO₂ out.