In case of vapour compression refrigeration system, elevating the evaporator temperature (keeping the condenser temperature constant) results in
A. Enhanced COP
B. Decreased COP
C. No change in the value of COP
D. Increased or decreased COP ; depending upon the type of refrigerant
Select an option to see the answer and solution.
Melting of ice is an example of an __________ process.
A. Adiabatic
B. Isothermal
C. Isometric
D. None of these
Select an option to see the answer and solution.
Claude's liquefaction process employs the cooling of gases by
A. Expansion in an engine
B. Following a constant pressure cycle
C. Throttling
D. None of these
Select an option to see the answer and solution.
A domestic refrigerator has a/an __________ cooled condenser.
A. Water
B. Air
C. Evaporative
D. Gas
Select an option to see the answer and solution.
Pressure-enthalpy chart is useful in refrigeration. The change in internal energy of an ideal fluid used in ideal refrigeration cycle is
A. Positive
B. Negative
C. Zero
D. Infinity
Select an option to see the answer and solution.
At normal boiling point, molar entropy of vaporisation is __________ Joule/K°.mole.
Select an option to see the answer and solution.
PVy = constant, holds good for an isentropic process, which is
A. Reversible and isothermal
B. Isothermal and irreversible
C. Reversible and adiabatic
D. Adiabatic and irreversible
Select an option to see the answer and solution.
The internal energy of an ideal gas is a function of its __________ only.
A. Molecular size
B. Volume
C. Pressure
D. Temperature
Select an option to see the answer and solution.
Gibbs free energy at constant pressure and temperature under equilibrium conditions is
Select an option to see the answer and solution.
Free energy change at equilibrium is
A. Zero
B. Positive
C. Negative
D. Indeterminate
Select an option to see the answer and solution.
In jet refrigerators, the refrigerating fluid is practically always
A. Water
B. Ammonia
C. Freon
D. Brine
Select an option to see the answer and solution.
In the reaction; N2 + O2 ⇋ 2NO, increasing the pressure will result in
A. Shifting the equilibrium towards right
B. Shifting the equilibrium towards left
C. No change in equilibrium condition
D. None of these
Select an option to see the answer and solution.
Number of degrees of freedom for a three phase system in equilibrium comprising of three non-reacting chemical species is
Select an option to see the answer and solution.
Gibbs-Duhem equation relates composition in liquid phase and the __________ at constant temperature & pressure.
A. Fugacity
B. Partial pressure
C. Activity co-efficient
D. A, B, and C
Select an option to see the answer and solution.
For multicomponent multiple phases to be in equilibrium at the same pressure and temperature, the __________ of each component must be same in all phases.
A. Chemical potential
B. Fugacity
C. Both A and B
D. Neither A nor B
Select an option to see the answer and solution.
Chemical potential (an intensive property) of a substance is a force that drives the chemical system to equilibrium and is equal to its partial molar properties. The reatio of chemical potential to free energy of a pure substance at oconstant temperature and pressure is
Select an option to see the answer and solution.
One ton of refrigeration capacity is equivalent to the heat removal rate of
A. 50 kcal/hr
B. 200 BTU/hr
C. 200 BTU/minute
D. 200 BTU/day
Select an option to see the answer and solution.
Internal energy of an ideal gas
A. Increases with increase in pressure
B. Decreases with increase in temperature
C. Is independent of temperature
D. None of these
Select an option to see the answer and solution.
In an ideal refrigeration cycle, the change in internal energy of the fluid is
A. +ve
B. -ve
C. 0
D. Either of the above three ; depends on the nature of refrigerant
Select an option to see the answer and solution.
In a reversible chemical reaction (where, Δx = number of moles of products-number of moles of reactants )
A. Addition of inert gas favours the forward reaction, when Δx is positive
B. Pressure has no effect on equilibrium, when Δn = 0
C. Addition of inert gas has no effect on the equilibrium constant at constant volume for any value of Δx (+ ve, - ve) or zero)
D. All of the above
Select an option to see the answer and solution.