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What is the correct answer?

4

In vapour compression refrigeration system, if the evaporator temperature and the condenser temperatures are -13°C and 37°C respectively, the Carnot COP will be

A. 5.2

B. 6.2

C. 0.168

D. Data insufficient, can't be found out

Correct Answer :

A. 5.2


Related Questions

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4

Thermal efficiency of a Carnot engine can approach 100%, only when the temperature of the

A. Cold reservoir approaches zero

B. Hot reservoir approaches infinity

C. Either (A) or (B)

D. Neither (A) nor (B)

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4

dW and dq are not the exact differential, because q and W are

A. State functions

B. Path functions

C. Intensive properties

D. Extensive properties

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4

There is a change in __________ during the phase transition.

A. Volume

B. Pressure

C. Temperature

D. All a, b & c

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4

Pick out the correct statement.

A. The available energy in an isolated system for all irreversible (real) processes decreases

B. The efficiency of a Carnot engine increases, if the sink temperature is decreased

C. The reversible work for compression in non-flow process under isothermal condition is the change in Helmholtz free energy

D. All (A), (B) and (C)

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4

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

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4

Linde gas liquefaction process employs cooling

A. By throttling

B. By expansion in an engine

C. At constant pressure

D. None of these

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4

The value of gas constant 'R' is

A. 1.987 cal/gm mole °K

B. 1.987 BTU/lb. mole °R

C. Both (A) and (B)

D. Neither (A) nor (B)

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4

Which of the following equations is obtained on combining 1st and 2nd law of thermodynamics, for a system of constant mass?

A. dE = Tds - PdV

B. dQ = CvdT + PdV

C. dQ = CpdT + Vdp

D. Tds = dE - PdV

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4

Pick out the wrong statement.

A. The conversion for a gas phase reaction increases with decrease in pressure, if there is an increase in volume accompanying the reaction

B. With increase in temperature, the equilibrium constant increases for an exothermic reaction

C. The equilibrium constant of a reaction depends upon temperature only

D. The conversion for a gas phase reaction increases with increase in pressure, if there is a decrease in volume accompanying the reaction

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4

The temperature at which a real gas obeys the ideal gas laws over a wide range of pressure is called the __________ temperature.

A. Critical

B. Boyle

C. Inversion

D. Reduced

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4

Fugacity is most helpful in

A. Representing actual behaviour of real gases

B. Representing actual behaviour of ideal gases

C. The study of chemical equilibria involving gases at atmospheric pressure

D. None of these

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4

In case of a close thermodynamic system, there is __________ across the boundaries.

A. No heat and mass transfer

B. No mass transfer but heat transfer

C. Mass and energy transfer

D. None of these

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4

Molar heat capacity of water in equilibrium with ice at constant pressure is __________ Kcal/kg mole. °K

A. 0

B.

C. 50

D. 100

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4

For an ideal liquid solution, which of the following is unity?

A. Activity

B. Fugacity

C. Activity co-efficient

D. Fugacity co-efficient

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4

In case of an __________ process, the temperature of the system increases.

A. Isothermal compression

B. Isothermal expansion

C. Adiabatic expansion

D. Adiabatic compression

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4

Specific __________ does not change during phase change at constant temperature and pressure.

A. Entropy

B. Gibbs energy

C. Internal energy

D. Enthalpy

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4

The quantitative effect of temperature on chemical equilibrium is given by the

A. Vant-Hoff equation

B. Le-Chatelier's principle

C. Arrhenius equation

D. None of these

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4

Entropy of a substance remains constant during a/an __________ change.

A. Reversible isothermal

B. Irreversible isothermal

C. Reversible adiabatic

D. None of these

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4

Which of the following is not a common refrigerant?

A. Freon-12

B. Ethylene

C. Ammonia

D. Carbon dioxide

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4

Critical solution temperature (or the consolute temperature) for partially miscible liquids (e.g., phenol-water) is the minimum temperature at which

A. A homogeneous solution (say of phenol water) is formed

B. Mutual solubility of the two liquids shows a decreasing trend

C. Two liquids are completely separated into two layers

D. None of these

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4

The first law of thermodynamics is a statement of conservation of

A. Heat

B. Momentum

C. Energy

D. Work

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4

The Carnot co-efficient of performance (COP) of a domestic air conditioner compared to a household refrigerator is

A. Less

B. More

C. Same

D. Dependent on climatic conditions

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4

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

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4

Out of the following refrigeration cycles, which one has the minimum COP (Co-efficient of performance)?

A. Air cycle

B. Carnot cycle

C. Ordinary vapour compression cycle

D. Vapour compression with a reversible expansion engine

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4

For an ideal solution, the value of activity co-efficient is

A. 0

B. 1

C. < 1

D. > 1

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4

Pick out the extensive property out of the following.

A. Surface tension

B. Free energy

C. Specific heat

D. Refractive index

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4

The first law of thermodynamics is a restatement of the law of conservation of

A. Mass

B. Energy

C. Momentum

D. None of these

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4

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 ratio of chemical potential to free energy of a pure substance at constant temperature and pressure is

A. 0

B. 1

C.

D. None of these

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4

y = specific heat ratio of an ideal gas is equal to

A. Cp/Cv

B. Cp/(CP-R)

C. 1 + (R/CV)

D. All (A), (B) and (C)

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4

Pick out the wrong statement:

A. The expansion of a gas in vacuum is an irreversible process

B. An isometric process is a constant pressure process

C. Entropy change for a reversible adiabatic process is zero

D. Free energy change for a spontaneous process is negative