1061. For a thermodynamic system going through a process, which of the following pairs best exemplifies a relationship similar to that of the pair “pressure-volume”?
A. Pressure-enthalpy
B. Enthalpy-entropy
C. Temperature-entropy *
D. Pressure-temperature
1062. During isothermal expansion of gas in a cylinder, several values of pressure and corresponding volume are recorded . What will be the nature of curve if volume is plotted as ordinate and inverse of pressure as abscissa ?
A. A parabola *
B. A hyperbola
C. A straight line through origin
D. A straight line with intercept on a vertical axis
1063. With 1000 % increase in pressure during adiabatic expression, the temperature increase is found to be 100 % . The following is the ratio of specific heats:
A. 1.3
B. 1.2
C. 1.4 *
D. 1.5
1064. What fraction of heat supplied is converted into work during a constant pressure heating process ? (Take y = 1.4):
A. 0.25
B. 0.275
C. 0.30
D. 0.325 *
1065. Measurement showed that during a polytropic expansion process , The work obtained was 1.8 times the heat transferred . Taking adiabatic index y = 1.4, what would be the expansion index for the polytropic process :
A. 1.15 *
B. 1.25
C. 1.35
D. 1.45
1066. Increase in entropy of a system represents :
A. Increase in temperature
B. Increase in pressure
C. Increase in available energy
D. Degradation of energy *
1067. The third law of thermodynamics :
A. Defines internal energy
B. Provides a base from which entropy is measured *
C. Gives availability of heat for conversion into work
D. Determines whether a procedure can be reversed or not.
1068. Which amongst the following gases has the lowest value of characteristic gas constant ?
A. Hydrogen
B. Nitrogen
C. Air
D. Carbon dioxide *
1069. During adiabatic cooling of moist air :
A. DBT remains constant
B. Specific humidity remains constant
C. Relative humidity remains constant
D. WBT remains constant
1070. For a refrigerant being used in a vapour compression refrigeration system , the joule thomson coefficient should be :
A. Positive
B. Negative *
C. Zero
D. Infinity