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A vapour absorption refrigerator uses __________ as a refrigerant.

A. Water

B. Ammonia

C. Freon

D. Aqua-ammonia

Correct Answer :

D. Aqua-ammonia


Related Questions

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The specific humidity during dehumidification process

A. Remains constant

B. Increases

C. Decreases

D. None of these

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4

Superheating in a refrigeration cycle

A. Increases C.O.P

B. Decreases C.O.P

C. C.O.P remains unaltered

D. Other factors decide C.O.P

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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

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

The general rule for rating refrigeration systems (excepting for CO₂ system) is to approximate following h.p. per ton of refrigeration

A. 0.1 to 0.5 h.p. per ton of refrigeration

B. 0.5 to 0.8 h.p. per ton of refrigeration

C. 1 to 2 h.p. per ton of refrigeration

D. 2 to 5 h.p. per ton of refrigeration

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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 is not a desirable property of a refrigerant?

A. High risibility with oil

B. Low boiling point

C. Good electrical conductor

D. Large latent heat

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4

In a vapour compression system, the condition of refrigerant is dry saturated vapour

A. Before entering the compressor

B. After leaving the compressor

C. Before entering the condenser

D. After leaving the condenser

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4

The temperature of ammonia after compression in a vapour compression system is

A. 20 to 50°C

B. 50 to 70°C

C. 70 to 110°C

D. None of these

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An Electrolux refrigerator is called a __________ absorption system.

A. Single fluid

B. Two fluids

C. Three fluids

D. None of these

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Absorption system normally uses the following refrigerant

A. Freon-11

B. Freon-22

C. CO2

D. Ammonia

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4

A certain refrigerating system has a normal operating suction pressure of 10 kg/cm gauge and condensing pressure of about 67 kg/cm. The refrigerant used is

A. Ammonia

B. Carbon dioxide

C. Freon

D. Brine

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4

The superheated vapour region, in a pressure enthalpy chart, is represented by the space

A. To the left of saturated liquid line

B. To the right of saturated liquid line

C. Between the saturated liquid line and saturated vapour line

D. None of the above

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As relative humidity decreases, the dew point temperature will be ________ wet bulb temperature.

A. Same as

B. Lower than

C. Higher than

D. None of these

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An important characteristic of absorption system of refrigeration is

A. Noisy operation

B. Quiet operation

C. Cooling below 0°C

D. Very little power consumption

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4

An infinite parallel planes with emissivities e₁ and e₂, the interchange factor for radiation from surface 1 to surface 2 is given by

A. (e₁ + e₂)/ e₁ + e₂ - e₁e₂

B. 1/e₁ + 1/e₂

C. e₁ + e₂

D. e₁e₂

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4

The reduced ambient air cooling system has

A. One cooling turbine and one heat exchanger

B. One cooling turbine and two heat exchangers

C. Two cooling turbines and one heat exchanger

D. Two cooling turbines and two heat exchangers

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4

The boiling point of ammonia is

A. 100°C

B. 50°C

C. 33.3°C

D. 0°C

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4

The freezing point of sulphur dioxide is

A. -56.6°C

B. -75.2°C

C. -77.7°C

D. -135.8°C

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4

In a bootstrap air evaporative cooling system, the evaporator is provided

A. Between the combustion chamber and the first heat exchanger

B. Between the first heat exchanger and the secondary compressor

C. Between the secondary compressor and the second heat exchanger

D. Between the second heat exchanger and the cooling turbine

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4

If a heat pump cycle operates between the condenser temperature of +27°C and evaporator temperature of -23°C, then the Carnot COP will be

A. 0.2

B. 1.2

C. 5

D. 6

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4

The condition of refrigerant after passing through the condenser in a vapour compression system is

A. Saturated liquid

B. Wet vapour

C. Dry saturated vapour

D. Superheated vapour

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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

A pressure gauge on the discharge side of a refrigerant compressor reads too high. The reasons will be

A. Lack of cooling water

B. Water temperature being high

C. Dirty condenser surface

D. All of these

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4

The ratio of actual mass of water vapour in a given volume of moist air to the mass of water vapour in the same volume of saturated air at the same temperature and pressure, is called

A. Humidity ratio

B. Relative humidity

C. Absolute humidity

D. Degree of saturation

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The vapour pressure of refrigerant should be

A. Lower than atmospheric pressure

B. Higher than atmospheric pressure

C. Equal to atmospheric pressure

D. Could be anything

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4

Which of the following statement is correct for ammonia as a refrigerant?

A. It is toxic to mucous membranes.

B. It requires large displacement per TR compared to fluoro carbons.

C. It reacts with copper and its alloys.

D. All of these

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4

The index which correlates the combined effects of air temperature, relative humidity and air velocity on the human body, is known as

A. Mean radiant temperature

B. Effective temperature

C. Dew point temperature

D. None of these

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4

Air conditioning means

A. Cooling

B. Heating

C. Dehumidifying

D. All of these

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The emissivity of a polished silver body is __________ as compared to black body.

A. Same

B. Low

C. Very low

D. High