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What is the correct answer?

4

Pick out the wrong statement.

A. A refrigeration cycle violates the second law of thermodynamics

B. Refrigeration cycle is normally represented by a temperature vs. entropy plot

C. In a refrigerator, work required decreases as the temperature of the refrigerator and the temperature at which heat is rejected increases

D. One ton of refrigeration is equivalent to the rate of heat absorption equal to 3.53 kW

Correct Answer :

A. A refrigeration cycle violates the second law of thermodynamics


Related Questions

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4

The molar excess Gibbs free energy, gE, for a binary liquid mixture at T and P is given by, (gE/RT) = A . x1. x2, where A is a constant. The corresponding equation for ln y1, where y1 is the activity co-efficient of component 1, is

A. A . x22

B. Ax1

C. Ax2

D. Ax12

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4

A refrigeration cycle is the same as a __________ cycle,

A. Turbine

B. Heat engine

C. Reversed heat engine

D. None of these

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4

Isentropic process means a constant __________ process.

A. Enthalpy

B. Pressure

C. Entropy

D. None of these

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Heat is added at constant temperature in an ideal __________ cycle.

A. Stirling

B. Brayton

C. Rankine

D. None of these

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4

Joule-Thomson co-efficient depends on the

A. Pressure

B. Temperature

C. Both (A) & (B)

D. Neither (A) nor (B)

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4

A/an __________ system is exemplified by a vessel containing a volatile liquid in contact with its vapor.

A. Isolated

B. Closed

C. Open

D. None of these

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4

As the temperature is lowered towards the absolute zero, the value of the quantity (∂ΔF/∂T) approaches

A. Zero

B. Unity

C. Infinity

D. None of these

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4

For a cyclic process, a fixed ratio between heat and work

A. Always exists

B. May exist

C. Never exists

D. Is difficult to predict

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4

A gas shows deviation from ideal behaviour at

A. Low pressure and high temperature

B. Low pressure and low temperature

C. Low temperature and high pressure

D. High temperature and high pressure

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4

Domestic refrigerator usually works on the __________ refrigeration cycle.

A. Carnot

B. Air

C. Absorption

D. vapour-ejection

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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

For a constant volume process __________ by the system is used only to increase the internal energy.

A. Heat absorbed

B. Work done

C. Both (A) & (B)

D. Neither (A) nor (B)

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4

The kinetic energy of gas molecule is zero at

A. 0°C

B. 273°C

C. 100°C

D. -273°C

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4

Extensive properties of a thermodynamic system depend upon the __________ of the system.

A. Specific volume

B. Temperature

C. Mass

D. Pressure

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4

The internal energy of a gas obeying P (V - b) RT (where, b is a positive constant and has a constant Cv), depends upon its

A. Pressure

B. Volume

C. Temperature

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

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4

If the vapour pressure at two temperatures of a solid phase in equilibrium with its liquid phase are known, then the latent heat of fusion can be calculated by the

A. Maxwell's equation

B. Clausius-Clapeyron Equation

C. Van Laar equation

D. Nernst Heat Theorem

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4

Chemical potential is a/an

A. Extensive property

B. Intensive property

C. Force which drives the chemical system to equilibrium

D. Both (B) and (C)

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4

Tea kept in a thermos flask is vigorously shaken. If the tea is considered as a system, then its temperature will

A. Increase

B. Decrease

C. Remain unchanged

D. First fall and then rise

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4

A solid metallic block weighing 5 kg has an initial temperature of 500°C. 40 kg of water initially at 25°C is contained in a perfectly insulated tank. The metallic block is brought into contact with water. Both of them come to equilibrium. Specific heat of block material is 0.4 kJ.kg-1. K-1. Ignoring the effect of expansion and contraction and also the heat capacity to tank, the total entropy change in kJ.kg-1, K-1 is

A. -1.87

B. 0

C. 1.26

D. 3.91

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4

The heat capacities for the ideal gas state depend upon the

A. Pressure

B. Temperature

C. Both (A) & (B)

D. Neither (A) nor (B)

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4

Chemical potential of ith component of a system is given by

A. μi = (∂F/∂ni)T, P, ni

B. μi = (∂A/∂ni)T, P, ni

C. μi = (∂F/∂ni)T, P

D. μi = (∂A/∂ni)T, P

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4

Which is not constant for an ideal gas?

A. (∂P/∂V)T

B. (∂V/∂T)P

C. (∂P/∂V)V

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

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4

Consider the process A & B shown in the figure given below: In this case, it is possible that

A. Both the processes are adiabatic

B. Both the processes are isothermal

C. Process A is isothermal while B is adiabatic

D. Process A is adiabatic while B is isothermal

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4

All gases except __________ shows a cooling effect during throttling process at atmospheric temperature and pressure.

A. Oxygen

B. Nitrogen

C. Air

D. Hydrogen

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4

Which of the following units is not present in both the vapor compression refrigeration system and absorption refrigeration system?

A. Expansion valve

B. Condenser

C. Refrigerator

D. Compressor

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4

The absolute entropy for all crystalline substances at absolute zero temperature is

A. Zero

B. Negative

C. More than zero

D. Indeterminate

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4

For a given substance at a specified temperature, activity is __________ to fugacity.

A. Directly proportional

B. Inversely proportional

C. Equal

D. None of these

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4

Refrigeration cycle

A. Violates second law of thermodynamics

B. Involves transfer of heat from low temperature to high temperature

C. Both (A) and (B)

D. Neither (A) nor (B)

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4

What is the value of maximum COP in case of absorption refrigeration, if refrigeration provided is at temperature, TR (where, T1 and T2 are source & surrounding temperatures respectively.)?

A. TR/(T2 - TR) × (T1 - T2)/T1

B. TR/(T2 - TR) × T1/(T1 - T2)

C. TR/(T1 - TR) × (T1 - T2)/T1

D. None of these

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4

A solid is transformed into vapour without going to the liquid phase at

A. Triple point

B. Boiling point

C. Below triple point

D. Always