Home
Current Affairs January 2024

What is the correct answer?

4

Vertical lines on pressure-enthalpy chart show constant

A. Pressure lines

B. Temperature lines

C. Total heat lines

D. Entropy lines

Correct Answer :

C. Total heat lines


Related Questions

What is the correct answer?

4

Which of the following refrigerant has the lowest boiling point?

A. Ammonia

B. Carbon dioxide

C. Sulphur dioxide

D. R-12

What is the correct answer?

4

Air refrigeration cycle is used in

A. Commercial refrigerators

B. Domestic refrigerators

C. Air-conditioning

D. Gas liquefaction

What is the correct answer?

4

A condenser of refrigeration system rejects heat at the rate of 120 kW, while its compressor consumes a power of 30 kW. The coefficient of performance of the system will be

A. 1/4

B. 1/3

C. 3

D. 4

What is the correct answer?

4

The boiling point of ________ is 10.5°C.

A. Ammonia

B. R-12

C. Sulphur dioxide

D. Carbon dioxide

What is the correct answer?

4

During sensible heating of air _________ decreases.

A. Wet bulb temperature

B. Relative humidity

C. Dry bulb temperature

D. Specific humidity

What is the correct answer?

4

For obtaining high COP, the pressure range of compressor should be

A. High

B. Low

C. Optimum

D. Any value

What is the correct answer?

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

What is the correct answer?

4

The boiling point of ammonia is

A. 100°C

B. 50°C

C. 33.3°C

D. 0°C

What is the correct answer?

4

The humidity ratio or specific humidity is the mass of water vapour present in

A. 1 m3 of wet air

B. 1 m3 of dry air

C. 1 kg of wet air

D. 1 kg of dry air

What is the correct answer?

4

Under cooling 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

What is the correct answer?

4

In aqua ammonia absorption refrigeration system, incomplete rectification leads to accumulation of water in

A. Condenser

B. Evaporator

C. Absorber

D. None of these

What is the correct answer?

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

What is the correct answer?

4

The pressure at the outlet of a refrigerant compressor is called

A. Suction pressure

B. Discharge pressure

C. Critical pressure

D. Back pressure

What is the correct answer?

4

One ton of the refrigeration is

A. The standard unit used in refrigeration problems

B. The cooling effect produced by melting 1 ton of ice

C. The refrigeration effect to freeze 1 ton of water at 0°C into ice at 0°C in 24 hours

D. The refrigeration effect to produce 1 ton of ice at NTP conditions

What is the correct answer?

4

In a refrigerating machine, heat rejected is _________ heat absorbed.

A. Equal to

B. Less than

C. Greater than

D. None of these

What is the correct answer?

4

The evaporator used in household refrigerators is

A. Frosting evaporator

B. Non-frosting evaporator

C. Defrosting evaporator

D. None of these

What is the correct answer?

4

The bypass factor, in case of sensible cooling of air, is given by (where td₁ = Dry bulb temperature of air entering the cooling coil, td₂ = Dry bulb temperature of air leaving the cooling coil, and td₃ = Dry bulb temperature of the cooling coil)

A. (td₁ -td₃)/( td₂ -td₃)

B. (td₂ -td₃)/( td₁ -td₃)

C. (td₃ -td₁)/( td₂ -td₃)

D. (td₃ -td₂)/( td₁ -td₃)

What is the correct answer?

4

The capillary tube is not used in large capacity refrigeration systems because

A. Cost is too high

B. Capacity control is not possible

C. It is made of copper

D. Required pressure drop cannot be achieved

What is the correct answer?

4

The freezing point of sulphur dioxide is

A. -56.6°C

B. -75.2°C

C. -77.7°C

D. -135.8°C

What is the correct answer?

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

What is the correct answer?

4

An evaporator is also known as

A. Freezing coil

B. Cooling coil

C. Chilling coil

D. All of these

What is the correct answer?

4

The coefficient of performance is the ratio of the refrigerant effect to the

A. Heat of compression

B. Work done by compressor

C. Enthalpy increase in compressor

D. All of the above

What is the correct answer?

4

Moisture in Freon refrigeration system causes

A. Ineffective refrigeration

B. High power consumption

C. Freezing automatic regulating valve

D. Corrosion of whole system

What is the correct answer?

4

In a vapour compression system, the condition of refrigerant before passing through the condenser is

A. Saturated liquid

B. Wet vapour

C. Dry saturated vapour

D. Superheated vapour

What is the correct answer?

4

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

What is the correct answer?

4

The relative humidity lines on a psychrometric chart are

A. Vertical and uniformly spaced

B. Horizontal and uniformly spaced

C. Horizontal and non-uniformly spaced

D. Curved lines

What is the correct answer?

4

The C.O.P. of a refrigeration cycle with lowering of condenser temperature, keeping the evaporator temperature constant, will

A. Increase

B. Decrease

C. May increase or decrease depending on the type of refrigerant used

D. Remain unaffected

What is the correct answer?

4

Which of the following statement is correct?

A. In vapour absorption refrigerator, the compression of refrigerant is avoided.

B. Sub-cooling can be achieved by circulating more quantity of cooling water through the condenser.

C. In vapour compression refrigeration, the vapour is drawn in the compressor cylinder during its suction stroke and is compressed adiabatically during the compression stroke.

D. All of the above

What is the correct answer?

4

The wet bulb depression indicates _________ humidity of the air.

A. Absolute

B. Relative

C. Specific

D. None of these

What is the correct answer?

4

During heating and humidification, the final relative humidity of air

A. Can be lower or higher than that of the entering air

B. Is lower than that of the entering air

C. Is higher than that of the entering air

D. None of the above