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4

The Freon group of refrigerants are

A. Halocarbon refrigerants

B. Zoetrope refrigerants

C. Inorganic refrigerants

D. Hydrocarbon refrigerants

Correct Answer :

A. Halocarbon refrigerants


Related Questions

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4

The power per tonne of refrigeration is

A. 3.5/C.O.P.

B. C.O.P/3.5

C. 3.5 × C.O.P.

D. None of these

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4

In a pressure enthalpy chart, the space to the left of the saturated liquid line represents

A. Wet vapour region

B. Superheated vapour region

C. Sub-cooled liquid region

D. None of these

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4

Condensing temperature in a refrigerator is the temperature

A. Of cooling medium

B. Of freezing zone

C. Of evaporator

D. At which refrigerant gas becomes liquid

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4

Aqua ammonia is used as refrigerant in the following type of refrigeration system

A. Compression

B. Direct

C. Indirect

D. Absorption

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4

In a reversed Brayton cycle, the heat is absorbed by the air during

A. Isentropic compression process

B. Constant pressure cooling process

C. Isentropic expansion process

D. Constant pressure expansion process

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4

The atmospheric air at dry bulb temperature of 15°C enters a heating coil maintained at 40°C. The air leaves the heating coil at 25°C. The bypass factor of the heating coil is

A. 0.376

B. 0.4

C. 0.6

D. 0.67

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4

Accumulators should have adequate volume to store refrigerant charge at least

A. 10 %

B. 25 %

C. 50 %

D. 75 %

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4

In a flooded evaporator refrigerator, an accumulator at suction of compressor is used to

A. Collect liquid refrigerant and prevent it from going to compressor

B. Detect liquid in vapour

C. Superheat the vapour

D. Collect vapours

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4

One ton of refrigeration is equal to the refrigeration effect corresponding to melting of 1000 kg of ice

A. In 1 hour

B. In 1 minute

C. In 24 hours

D. In 12 hours

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4

Dry bulb temperature is the temperature of air recorded by a thermometer, when

A. It is not affected by the moisture present in the air

B. Its bulb is surrounded by a wet cloth exposed to the air

C. The moisture present in it begins to condense

D. None of the above

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4

The dehumidification process, on the psychrometric chart, is shown by

A. Horizontal line

B. Vertical line

C. Inclined line

D. Curved line

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4

At lower temperatures and pressures, the latent heat of vaporisation of a refrigerant

A. Decreases

B. Increases

C. Remain same

D. Depends on other factors

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4

The reciprocating refrigerant compressors are very suitable for

A. Small displacements and low condensing pressures

B. Large displacements and high condensing pressures

C. Small displacements and high condensing pressures

D. Large displacements and low condensing pressures

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4

Domestic refrigerator working on vapour compression cycle uses the following type of expansion device

A. Electrically operated throttling valve

B. Manually operated valve

C. Thermostatic valve

D. Capillary tube

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4

When the lower temperature of a refrigerating machine is fixed, then the coefficient of performance can be improved by

A. Operating the machine at higher speeds

B. Operating the machine at lower speeds

C. Raising the higher temperature

D. Lowering the higher temperature

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4

When the air is passed through an insulated chamber having sprays of water maintained at a temperature higher than the dew point temperature of entering air but lower than its dry bulb temperature, then the air is said to be

A. Cooled and humidified

B. Cooled and dehumidified

C. Heated and humidified

D. Heated and dehumidified

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4

Which of the following refrigerants has lowest freezing point?

A. Freon-12

B. NH3

C. CO2

D. Freon-22

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4

Reducing suction pressure in refrigeration cycle

A. Lowers evaporation temperature

B. Increases power required per ton of refrigeration

C. Lowers compressor capacity because vapour is lighter

D. All of the above

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4

For better C.O.P of refrigerator, the pressure range corresponding to temperature in evaporator and condenser must be

A. Small

B. High

C. Equal

D. Anything

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4

Chaperon equation is a relation between

A. Temperature, pressure and enthalpy

B. Specific volume and enthalpy

C. Temperature and enthalpy

D. Temperature, pressure, specific volume and enthalpy

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4

A bootstrap air cooling system has

A. One heat exchanger

B. Two heat exchangers

C. Three heat exchangers

D. Four heat exchangers

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4

The specific humidity during dehumidification process

A. Remains constant

B. Increases

C. Decreases

D. None of these

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4

Cooling water is required for following equipment in ammonia absorption plant

A. Condenser

B. Evaporator

C. Absorber

D. Condenser, absorber and separator (rectifier)

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4

The lower horizontal line of the refrigeration cycle plotted on pressure-enthalpy diagram represents

A. Condensation of the refrigerant vapour

B. Evaporation of the refrigerant liquid

C. Compression of the refrigerant vapour

D. Metering of the refrigerant liquid

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4

The wet bulb depression is zero when relative humidity is

A. Zero

B. 0.5

C. 0.75

D. 1.0

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4

The sensible heat factor during the heating and humidification process is given by (where h₁ = Enthalpy of air entering the heating coil, h₂ = Enthalpy of air leaving the heating coil, and hA = Enthalpy of air at the end of humidification process)

A. (hA - h2)/ (h1 - h2)

B. (h2 - hA)/ (h1 - h2)

C. (h1 - h2)/ (hA - h2)

D. (hA - h1)/ (h2 - h1)

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4

In a vapour compression refrigeration system, a throttle valve is used in place of an expander because

A. It considerably reduces mass of the system

B. It improves the C.O.P., as the condenser is small

C. The positive work in isentropic expansion of liquid is very small

D. It leads to significant cost reduction

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4

The capacity of a domestic refrigerator is in the range of

A. 0.1 to 0.3 TR

B. 1 to 3 TR

C. 3 to 5 TR

D. 5 to 7 TR

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4

In a domestic refrigerator, a capillary tube controls the flow of refrigerant from the

A. Expansion valve to the evaporator

B. Evaporator to the thermostat

C. Condenser to the expansion valve

D. Condenser to the evaporator

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4

The condition of refrigerant after passing through the expansion or throttle valve, in a vapour compression system is

A. High pressure saturated liquid

B. Wet vapour

C. Very wet vapour

D. Dry vapour