50 + Mcqs in IC Engines, Refrigeration and Air conditioning Page 1 McqOptions

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

Discussion

2.	The refrigerant used for absorption refrigerators working on heat from solar collectors is a mixture of water and
A.	Carbon dioxide
B.	Sulphur dioxide
C.	Lithium bromide
D.	R-12
Answer» D. R-12

Discussion

3.	Highest pressure encountered in a refrigeration system should be
A.	Critical pressure of refrigerant
B.	Much below critical pressure
C.	Much above critical pressure
D.	Near critical pressure
Answer» C. Much above critical pressure

Discussion

4.	In aircraft, air refrigeration Cycle is used because of
A.	Low weight per tonne of refrigeration
B.	High heat transfer rate
C.	Low temperature at high altitudes
D.	Higher coefficient of performance
Answer» B. High heat transfer rate

Discussion

5.	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
Answer» E.

Discussion

6.	The pressure at the inlet of a refrigerant compressor is called
A.	Suction pressure
B.	Discharge pressure
C.	Critical pressure
D.	Back pressure
Answer» B. Discharge pressure

Discussion

7.	Pick up the wrong statement. A refrigerant should have
A.	Tow specific heat of liquid
B.	High boiling point
C.	High latent heat of vaporisation
D.	Higher critical temperature
Answer» C. High latent heat of vaporisation

Discussion

8.	Hydrogen is used in Electrolux refrigeration system so as to _________ the rate of evaporation of the liquid ammonia passing through the evaporator.
A.	Equalize
B.	Reduce
C.	Increase
D.	None of these
Answer» D. None of these

Discussion

9.	If the evaporator temperature of a plant is lowered, keeping the condenser temperature constant, the h.p. of compressor required will be
A.	Same
B.	More
C.	Less
D.	More/less depending on rating
Answer» C. Less

Discussion

10.	Which of the following refrigerant has the maximum ozone depletion potential in the stratosphere?
A.	Ammonia
B.	Carbon dioxide
C.	Sulphur dioxide
D.	Fluorine
Answer» E.

Discussion

11.	In vapour compression cycle, the condition of refrigerant is saturated liquid
A.	After passing through the condenser
B.	Before passing through the condenser
C.	After passing through the expansion throttle valve
D.	Before entering the expansion valve
Answer» B. Before passing through the condenser

Discussion

12.	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
Answer» D. Two cooling turbines and two heat exchangers

Discussion

13.	The leaks in a refrigeration system using Freon are detected by
A.	Halide torch which on detection produces greenish flame lighting
B.	Sulphur sticks which on detection gives white smoke
C.	Using reagents
D.	Smelling
Answer» B. Sulphur sticks which on detection gives white smoke

Discussion

14.	The process, generally used in winter air-conditioning to warm and humidity the air, is called
A.	Humidification
B.	Dehumidification
C.	Heating and humidification
D.	Cooling and dehumidification
Answer» D. Cooling and dehumidification

Discussion

15.	One ton refrigeration corresponds to
A.	50 kcal/ min
B.	50 kcal/ hr
C.	80 kcal/ min
D.	80 kcal/ hr
Answer» B. 50 kcal/ hr

Discussion

16.	During sensible heating of air _________ decreases.
A.	Wet bulb temperature
B.	Relative humidity
C.	Dry bulb temperature
D.	Specific humidity
Answer» C. Dry bulb temperature

Discussion

17.	For proper refrigeration in a cabinet, if the temperature and vapour pressure difference between cabinet and atmosphere is high, then
A.	Bigger cabinet should be used
B.	Smaller cabinet should be used
C.	Perfectly tight vapour seal should be used
D.	Refrigerant with lower evaporation temperature should be used
Answer» D. Refrigerant with lower evaporation temperature should be used

Discussion

18.	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
Answer» E.

Discussion

19.	Which of the following statement is wrong?
A.	The performance of the vapour compression refrigerator varies considerably with both vaporising and condensing temperatures.
B.	In vapour compression cycle, the useful part of the heat transfer is at the condenser.
C.	In ammonia-hydrogen (Electrolux) refrigerator, no compressor, pump or fan is required.
D.	The effect of under-cooling the liquid refrigerant is to decrease the coefficient of performance
Answer» E.

Discussion

20.	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
Answer» C. Equal to atmospheric pressure

Discussion

21.	During humidification process, dry bulb temperature
A.	Remains constant
B.	Increases
C.	Decreases
D.	None of these
Answer» B. Increases

Discussion

22.	The C.O.P of a refrigeration cycle with increase in evaporator temperature, keeping condenser temperature constant, will
A.	Increase
B.	Decrease
C.	Remain unaffected
D.	May increase or decrease depending on the type of refrigerant used
Answer» B. Decrease

Discussion

23.	The wet bulb depression is zero when relative humidity is
A.	Zero
B.	0.5
C.	0.75
D.	1.0
Answer» E.

Discussion

24.	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
Answer» C. Remain same

Discussion

25.	During sensible cooling of air ________ decreases.
A.	Wet bulb temperature
B.	Relative humidity
C.	Dry bulb temperature
D.	Specific humidity
Answer» D. Specific humidity

Discussion

26.	The moisture in a refrigerant is removed by
A.	Evaporator
B.	Safety relief valve
C.	Dehumidifier
D.	Driers
Answer» E.

Discussion

27.	The refrigerant widely used in domestic refrigerators is
A.	Ammonia
B.	Carbon dioxide
C.	Sulphur dioxide
D.	R-12
Answer» E.

Discussion

28.	During dehumidification process, the relative humidity
A.	Remains constant
B.	Increases
C.	Decreases
D.	None of these
Answer» D. None of these

Discussion

29.	Rick up the incorrect statement
A.	Lithium bromide used in vapour absorption cycle is non volatile
B.	Lithium bromide plant cant operate below 0°C
C.	A separator is used in lithium bromide plant to remove the unwanted water vapour by condensing
D.	Concentration of solution coming out of lithium bromide generator is more in comparison to that entering the generator
Answer» D. Concentration of solution coming out of lithium bromide generator is more in comparison to that entering the generator

Discussion

30.	The centrifugal compressors are generally used for refrigerants that require
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
Answer» E.

Discussion

31.	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
Answer» C. Cooling below 0°C

Discussion

32.	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
Answer» D. Dry vapour

Discussion

33.	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
Answer» E.

Discussion

34.	The fluids used in Electrolux refrigerator are
A.	Water and hydrogen
B.	Ammonia and hydrogen
C.	Ammonia, water and hydrogen
D.	None of these
Answer» D. None of these

Discussion

35.	The COP of a vapour compression plant in comparison to vapour absorption plant is
A.	More
B.	Less
C.	Same
D.	More/less depending on size of plant
Answer» B. Less

Discussion

36.	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
Answer» B. Wet vapour

Discussion

37.	In a lithium bromide absorption refrigeration system
A.	Lithium bromide is used as a refrigerant and water as an absorbent
B.	Water is used as a refrigerant and lithium bromide as an absorbent
C.	Ammonia is used as a refrigerant and lithium bromide as an absorbent
D.	None of the above
Answer» C. Ammonia is used as a refrigerant and lithium bromide as an absorbent

Discussion

38.	The bank of tubes at the back of domestic refrigerator is
A.	Condenser tubes
B.	Evaporator tubes
C.	Refrigerant cooling tubes
D.	Capillary tubes
Answer» B. Evaporator tubes

Discussion

39.	A human body feels comfortable when the heat produced by the metabolism of human body is equal to the
A.	Heat dissipated to the surroundings
B.	Heat stored in the human body
C.	Sum of (A) and (B)
D.	Difference of (A) and (B)
Answer» D. Difference of (A) and (B)

Discussion

40.	Rating of a domestic refrigerator is of the order of
A.	0.1 ton
B.	5 tons
C.	10 tons
D.	40 tons
Answer» B. 5 tons

Discussion

41.	In actual air-conditioning applications for R-12 and R-22, and operating at a condenser temperature of 40° C and an evaporator temperature of 5° C, the heat rejection factor is about
A.	1
B.	1.25
C.	2.15
D.	5.12
Answer» C. 2.15

Discussion

42.	The vapour compression refrigerator employs the following cycle
A.	Rankine
B.	Carnot
C.	Reversed Rankine
D.	Reversed Carnot
Answer» E.

Discussion

43.	In a refrigeration system, the expansion device is connected between the
A.	Compressor and condenser
B.	Condenser and receiver
C.	Receiver and evaporator
D.	Evaporator and compressor
Answer» D. Evaporator and compressor

Discussion

44.	Mass flow ratio of NH₃ in comparison to Freon-12 for same refrigeration load and same temperature limits is of the order ofa
A.	1: 1
B.	1: 9
C.	9: 1
D.	1: 3
Answer» C. 9: 1

Discussion

45.	The freezing point of sulphur dioxide is
A.	-56.6°C
B.	-75.2°C
C.	-77.7°C
D.	-135.8°C
Answer» C. -77.7°C

Discussion

46.	Cooling water is required for following equipment in ammonia absorption plant
A.	Condenser
B.	Evaporator
C.	Absorber
D.	Condenser, absorber and separator (rectifier)
Answer» E.

Discussion

47.	A reversible engine has ideal thermal efficiency of 30%. When it is used as a refrigerating machine with all other conditions unchanged, the coefficient of performance will be
A.	1.33
B.	2.33
C.	3.33
D.	4.33
Answer» C. 3.33

Discussion

48.	For obtaining high COP, the pressure range of compressor should be
A.	High
B.	Low
C.	Optimum
D.	Any value
Answer» C. Optimum

Discussion

49.	The boiling point of ammonia is
A.	-10.5°C
B.	-30°C
C.	-33.3°C
D.	-77.7°C
Answer» D. -77.7°C

Discussion

50.	Freon group of refrigerants are
A.	Inflammable
B.	Toxic
C.	Non-inflammable and toxic
D.	Nontoxic and non-inflammable
Answer» E.

Discussion

Explore topic-wise MCQs in ENGINEERING SERVICES EXAMINATION (ESE).

One&nbsp;ton&nbsp;of&nbsp;the&nbsp;refrigeration&nbsp;is

&nbsp; The&nbsp;refrigerant&nbsp;used&nbsp;for&nbsp;absorption&nbsp;refrigerators&nbsp;working&nbsp;on&nbsp;heat&nbsp;from&nbsp;solar&nbsp;collectors&nbsp;is&nbsp;a&nbsp;mixture&nbsp;of&nbsp;water&nbsp;and &nbsp;

Highest&nbsp;pressure&nbsp;encountered&nbsp;in&nbsp;a&nbsp;refrigeration&nbsp;system&nbsp;should&nbsp;be

In&nbsp;aircraft,&nbsp;air&nbsp;refrigeration&nbsp;Cycle&nbsp;is&nbsp;used&nbsp;because&nbsp;of

Condensing&nbsp;temperature&nbsp;in&nbsp;a&nbsp;refrigerator&nbsp;is&nbsp;the&nbsp;temperature

&nbsp;The&nbsp;pressure&nbsp;at&nbsp;the&nbsp;inlet&nbsp;of&nbsp;a&nbsp;refrigerant&nbsp;compressor&nbsp;is&nbsp;called

Pick&nbsp;up&nbsp;the&nbsp;wrong&nbsp;statement.&nbsp;A&nbsp;refrigerant&nbsp;should&nbsp;have

&nbsp;Hydrogen&nbsp;is&nbsp;used&nbsp;in&nbsp;Electrolux&nbsp;refrigeration&nbsp;system&nbsp;so&nbsp;as&nbsp;to&nbsp;_________&nbsp;the&nbsp;rate&nbsp;of&nbsp;evaporation&nbsp;of&nbsp;the&nbsp;liquid&nbsp;ammonia&nbsp;passing&nbsp;through&nbsp;the&nbsp;evaporator.

&nbsp;If&nbsp;the&nbsp;evaporator&nbsp;temperature&nbsp;of&nbsp;a&nbsp;plant&nbsp;is&nbsp;lowered,&nbsp;keeping&nbsp;the&nbsp;condenser&nbsp;temperature&nbsp;constant,&nbsp;the&nbsp;h.p.&nbsp;of&nbsp;compressor&nbsp;required&nbsp;will&nbsp;be

Which&nbsp;of&nbsp;the&nbsp;following&nbsp;refrigerant&nbsp;has&nbsp;the&nbsp;maximum&nbsp;ozone&nbsp;depletion&nbsp;potential&nbsp;in&nbsp;the&nbsp;stratosphere?

&nbsp;In&nbsp;vapour&nbsp;compression&nbsp;cycle,&nbsp;the&nbsp;condition&nbsp;of&nbsp;refrigerant&nbsp;is&nbsp;saturated&nbsp;liquid

The&nbsp;reduced&nbsp;ambient&nbsp;air&nbsp;cooling&nbsp;system&nbsp;has

The&nbsp;leaks&nbsp;in&nbsp;a&nbsp;refrigeration&nbsp;system&nbsp;using&nbsp;Freon&nbsp;are&nbsp;detected&nbsp;by

The&nbsp;process,&nbsp;generally&nbsp;used&nbsp;in&nbsp;winter&nbsp;air-conditioning&nbsp;to&nbsp;warm&nbsp;and&nbsp;humidity&nbsp;the&nbsp;air,&nbsp;is&nbsp;called

One&nbsp;ton&nbsp;refrigeration&nbsp;corresponds&nbsp;to

During&nbsp;sensible&nbsp;heating&nbsp;of&nbsp;air&nbsp;_________&nbsp;decreases.

For&nbsp;proper&nbsp;refrigeration&nbsp;in&nbsp;a&nbsp;cabinet,&nbsp;if&nbsp;the&nbsp;temperature&nbsp;and&nbsp;vapour&nbsp;pressure&nbsp;difference&nbsp;between&nbsp;cabinet&nbsp;and&nbsp;atmosphere&nbsp;is&nbsp;high,&nbsp;then

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

Which&nbsp;of&nbsp;the&nbsp;following&nbsp;statement&nbsp;is&nbsp;wrong?

The&nbsp;vapour&nbsp;pressure&nbsp;of&nbsp;refrigerant&nbsp;should&nbsp;be

During&nbsp;humidification&nbsp;process,&nbsp;dry&nbsp;bulb&nbsp;temperature

The&nbsp;C.O.P&nbsp;of&nbsp;a&nbsp;refrigeration&nbsp;cycle&nbsp;with&nbsp;increase&nbsp;in&nbsp;evaporator&nbsp;temperature,&nbsp;keeping&nbsp;condenser&nbsp;temperature&nbsp;constant,&nbsp;will

The&nbsp;wet&nbsp;bulb&nbsp;depression&nbsp;is&nbsp;zero&nbsp;when&nbsp;relative&nbsp;humidity&nbsp;is

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

During&nbsp;sensible&nbsp;cooling&nbsp;of&nbsp;air&nbsp;________&nbsp;decreases.

The&nbsp;moisture&nbsp;in&nbsp;a&nbsp;refrigerant&nbsp;is&nbsp;removed&nbsp;by

The&nbsp;refrigerant&nbsp;widely&nbsp;used&nbsp;in&nbsp;domestic&nbsp;refrigerators&nbsp;is

During&nbsp;dehumidification&nbsp;process,&nbsp;the&nbsp;relative&nbsp;humidity

Rick&nbsp;up&nbsp;the&nbsp;incorrect&nbsp;statement

The&nbsp;centrifugal&nbsp;compressors&nbsp;are&nbsp;generally&nbsp;used&nbsp;for&nbsp;refrigerants&nbsp;that&nbsp;require

An&nbsp;important&nbsp;characteristic&nbsp;of&nbsp;absorption&nbsp;system&nbsp;of&nbsp;refrigeration&nbsp;is

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

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

The&nbsp;fluids&nbsp;used&nbsp;in&nbsp;Electrolux&nbsp;refrigerator&nbsp;are

The&nbsp;COP&nbsp;of&nbsp;a&nbsp;vapour&nbsp;compression&nbsp;plant&nbsp;in&nbsp;comparison&nbsp;to&nbsp;vapour&nbsp;absorption&nbsp;plant&nbsp;is

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

In&nbsp;a&nbsp;lithium&nbsp;bromide&nbsp;absorption&nbsp;refrigeration&nbsp;system

The&nbsp;bank&nbsp;of&nbsp;tubes&nbsp;at&nbsp;the&nbsp;back&nbsp;of&nbsp;domestic&nbsp;refrigerator&nbsp;is

A&nbsp;human&nbsp;body&nbsp;feels&nbsp;comfortable&nbsp;when&nbsp;the&nbsp;heat&nbsp;produced&nbsp;by&nbsp;the&nbsp;metabolism&nbsp;of&nbsp;human&nbsp;body&nbsp;is&nbsp;equal&nbsp;to&nbsp;the

Rating&nbsp;of&nbsp;a&nbsp;domestic&nbsp;refrigerator&nbsp;is&nbsp;of&nbsp;the&nbsp;order&nbsp;of

The&nbsp;vapour&nbsp;compression&nbsp;refrigerator&nbsp;employs&nbsp;the&nbsp;following&nbsp;cycle

In&nbsp;a&nbsp;refrigeration&nbsp;system,&nbsp;the&nbsp;expansion&nbsp;device&nbsp;is&nbsp;connected&nbsp;between&nbsp;the

Mass&nbsp;flow&nbsp;ratio&nbsp;of&nbsp;NH₃&nbsp;in&nbsp;comparison&nbsp;to&nbsp;Freon-12&nbsp;for&nbsp;same&nbsp;refrigeration&nbsp;load&nbsp;and&nbsp;same&nbsp;temperature&nbsp;limits&nbsp;is&nbsp;of&nbsp;the&nbsp;order&nbsp;ofa

The&nbsp;freezing&nbsp;point&nbsp;of&nbsp;sulphur&nbsp;dioxide&nbsp;is

Cooling&nbsp;water&nbsp;is&nbsp;required&nbsp;for&nbsp;following&nbsp;equipment&nbsp;in&nbsp;ammonia&nbsp;absorption&nbsp;plant

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

The&nbsp;boiling&nbsp;point&nbsp;of&nbsp;ammonia&nbsp;is

Freon&nbsp;group&nbsp;of&nbsp;refrigerants&nbsp;are

One ton of the refrigeration is

The refrigerant used for absorption refrigerators working on heat from solar collectors is a mixture of water and

Highest pressure encountered in a refrigeration system should be

In aircraft, air refrigeration Cycle is used because of

Condensing temperature in a refrigerator is the temperature

The pressure at the inlet of a refrigerant compressor is called

Pick up the wrong statement. A refrigerant should have

Hydrogen is used in Electrolux refrigeration system so as to _________ the rate of evaporation of the liquid ammonia passing through the evaporator.

If the evaporator temperature of a plant is lowered, keeping the condenser temperature constant, the h.p. of compressor required will be

Which of the following refrigerant has the maximum ozone depletion potential in the stratosphere?

In vapour compression cycle, the condition of refrigerant is saturated liquid

The reduced ambient air cooling system has

The leaks in a refrigeration system using Freon are detected by

The process, generally used in winter air-conditioning to warm and humidity the air, is called

One ton refrigeration corresponds to

During sensible heating of air _________ decreases.

For proper refrigeration in a cabinet, if the temperature and vapour pressure difference between cabinet and atmosphere is high, then

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

Which of the following statement is wrong?

The vapour pressure of refrigerant should be

During humidification process, dry bulb temperature

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

The wet bulb depression is zero when relative humidity is

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

During sensible cooling of air ________ decreases.

The moisture in a refrigerant is removed by

The refrigerant widely used in domestic refrigerators is

During dehumidification process, the relative humidity

Rick up the incorrect statement

The centrifugal compressors are generally used for refrigerants that require

An important characteristic of absorption system of refrigeration is

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

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

The fluids used in Electrolux refrigerator are

The COP of a vapour compression plant in comparison to vapour absorption plant is

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

In a lithium bromide absorption refrigeration system

The bank of tubes at the back of domestic refrigerator is

A human body feels comfortable when the heat produced by the metabolism of human body is equal to the

Rating of a domestic refrigerator is of the order of

The vapour compression refrigerator employs the following cycle

In a refrigeration system, the expansion device is connected between the

Mass flow ratio of NH₃ in comparison to Freon-12 for same refrigeration load and same temperature limits is of the order ofa

The freezing point of sulphur dioxide is

Cooling water is required for following equipment in ammonia absorption plant

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

The boiling point of ammonia is

Freon group of refrigerants are