4069. Which of the following exemplifies an adiabatic process?
A. Melting of ice
B. Condensation of alcohol vapor
C. Sudden bursting of a cycle tube
D. Evaporation of water
✅ The correct answer is option C.
4073. Entropy of the system decreases, when
A. Snow melts into water
B. A gas expands spontaneously from high pressure to low pressure
C. Water is converted into ice
D. Both B & C
✅ The correct answer is option D.
4078. The Maxwell relation derived from the differential expression for the Helmholtz free energy (dA) is
A. (∂T/∂V)S = -(∂P/∂S)V
B. (∂S/∂P)T = -(∂V/∂T)P
C. (∂V/∂S)P = (∂T/∂P)S
D. (∂S/∂V)T = (∂P/∂T)V
✅ The correct answer is option D.
4083. Change of heat content when one mole of compound is burnt in oxygen at constant pressure is called the
A. Calorific value
B. Heat of reaction
C. Heat of combustion
D. Heat of formation
✅ The correct answer is option C.
4088. Which of the following is not an equation of state?
A. Bertholet equation
B. Clausius Clayperon equation
C. Beattie-Bridgeman equation
D. None of these
✅ The correct answer is option B.
4054. For organic compounds, group contribution method can be used for the estimation of
A. Critical properties
B. Specific gravity
C. Specific volume
D. Thermal conductivity
✅ The correct answer is option A.
4060. The co-efficient of performance (COP) of a refrigerating system, which is its index of performance, is defined as the ratio of useful refrigeration to the net work. The units of __________ and COP are the same.
A. Kinematic viscosity
B. Work
C. Temperature
D. None of these
✅ The correct answer is option D.
4065. Heat evolved/absorbed during conversion of a substance from one allotropic form to another is termed as the heat of
A. Fusion
B. Vaporisation
C. Transition
D. None of these
✅ The correct answer is option C.
4070. Pick out the correct statement:
A. In an isothermal system, irreversible work is more than reversible work
B. Under reversible conditions, the adiabatic work is less than isothermal work
C. Heat, work, enthalpy and entropy are all ‘state functions’
D. Matter and energy can not be exchanged with the surroundings in a closed system
✅ The correct answer is option B.
4075. The point at which all the three (solid, liquid and gas) phases co-exist, is known as the __________ point.
A. Freezing
B. Triple
C. Boiling
D. Boyle
✅ The correct answer is option B.