Selected MCQ

Current Question
In thermodynamics, the Helmholtz free energy is minimized at constant:
  • A. Pressure and temperature
  • B. Volume and temperature
  • C. Volume and entropy
  • D. Pressure and entropy
Correct Answer: B
Explanation:
Helmholtz free energy applies to constant T and V systems.
Related Question 1
The partition function (Z) is related to Helmholtz free energy (F) by:
  • A. (F = kT \ln Z)
  • B. (F = -kT \ln Z)
  • C. (F = Z/kT)
  • D. (F = k/Z)
Correct Answer: B
Explanation:
Helmholtz free energy derives from partition function logarithm.
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 constant relates energy and frequency?
  • A. Boltzmann constant
  • B. Planck constant
  • C. Avogadro number
  • D. Gas constant
Correct Answer: B
Explanation:
(E = h\nu).
Related Question 4
Which thermodynamic potential is minimized at constant temperature and pressure?
  • A. Internal energy
  • B. Helmholtz free energy
  • C. Gibbs free energy
  • D. Enthalpy
Correct Answer: C
Explanation:
Gibbs free energy reaches minimum at equilibrium under constant T and P.
Related Question 5
Which energy source is sustainable?
  • A. Coal
  • B. Oil
  • C. Solar
  • D. Gas
Correct Answer: C
Explanation:
Solar is sustainable.