Quiz Questions

Question 1 1 Marks

Which two components do the compressor function in vapour absorption system?

A

Generator and absorber

B

Generator and separator

C

Generator and condenser

D

Generator and evaporator

Question 2 1 Marks

Which thermodynamic process the temperature is kept constant?

A

Isobaric process

B

Isothermal process

C

Constant volume process

D

Constant pressure process

Question 3 1 Marks

Which instrument is used to measure atmospheric pressure?

A

Hygrometer

B

Hydrometer

C

Manometer

D

Barometer

Question 4 1 Marks

What is the absolute pressure of gas in a cylinder, if gauge reads 135.3 p.s.i?

A

130 p.s.i.a

B

140 p.s.i.a

C

150 p.s.i.a

D

160 p.s.i.a

Question 5 1 Marks

What is the rate of doing work?

A

Duty

B

Force

C

Power

D

Velocity

Question 6 1 Marks

Which factors produce work?

A

Force and distance

B

Time and distance

C

Force and power

D

Force and time

Question 7 1 Marks

Which condition is maintained for refrigerant in high side of vapour compression system?

A

Above its critical temperature

B

Below its critical temperature

C

Above its freezing temperature

D

Below its freezing temperature

Question 8 1 Marks

Which instrument is used for measuring
heat?

A

Thermometer

B

Anemometer

C

Calorimeter

D

Ammeter

Question 9 1 Marks

What is the purpose of accumulator in a refrigerator?

A

Improves oil circulation

B

Prevents surging of refrigerant

C

Avoids hunting of refrigerant

D

Prevents liquid flood back to compressor

Question 10 1 Marks

What is the energy of a body by virtue of its position?

A

Wind energy

B

Kinetic energy

C

Potential energy

D

Electrical energy

Question 11 1 Marks

Which law is related to the constant PV at constant T?

A

Boyles law

B

Charles s law

C

Pascal s law

D

Renaults law

Question 12 1 Marks

What is the equivalent absolute scale for centigrade?

A

Kelvin

B

Celsius

C

Rankine

D

Fahrenheit

Question 13 1 Marks

Which component controls the thermostat and defrost heater in frost free refrigerator?

A

Thermoheater

B

Defrost timer

C

Relay

D

OLP

Question 14 1 Marks

What is the boiling point of pure water in centigrade scale?

A

212 Degree Centigrade

B

100 Degree Centigrade

C

32 Degree Centigrade

D

0 Degree Centigrade

Question 15 1 Marks

Which method is used to connect the swaged joint in copper tubes?

A

TIG welding

B

Silver brazing

C

Lead soldering

D

Fusion welding

Question 16 1 Marks

What is the capacity of doing work?

A

Work

B

Power

C

Force

D

Energy

Question 17 1 Marks

What is the absolute zero temperature in
degree centigrade?

A

0 Degree Centigrade

B

100 Degree Centigrade

C

-273 Degree Centigrade

D

212 Degree Centigrade

Question 18 1 Marks

What is bottom dead centre in reciprocating compressor cylinder?

A

The piston moves up from the point of cylinder

B

The piston stops in cylinder at top

C

The piston moves down from the point of cylinder

D

The piston starts in cylinder at top

Question 19 1 Marks

What is the atmospheric pressure at sea
level?

A

1.033 kg/cm2

B

1.3 Kg/cm2

C

1.5 Kg/cm2

D

1.6 Kg/cm2

Question 20 1 Marks

What is the barometer reading at sea level in Hg column?

A

760 mm

B

750 mm

C

740 mm

D

730 mm

Question 21 1 Marks

Which refrigeration system works on
directly by the heat energy?

A

Jet refrigeration

B

Mechanical refrigeration

C

Vapour absorption refrigeration

D

Vapour compression refrigeration

Question 22 1 Marks

What is effect of compression process on refrigerant vapour?

A

Heat the vapour below saturation

B

Cool the vapour above saturation

C

Increase the pressure and temperature

D

Decrease the pressure and temperature

Question 23 1 Marks

What is the unit of heat in M.K.S system?

A

B.T.U (British thermal unit)

B

K.Cal (Kilo Calorie)

C

KV (Kilo Volt)

D

K.W (Kilo Watt)

Question 24 1 Marks

How the level of heat in a substance is
expressed?

A

Micron

B

Pressure

C

Humidity

D

Temperature

Question 25 1 Marks

What is the physical state of ammonia at condenser inlet in vapour absorption system?

A

Solid

B

Liquid

C

Vapour

D

Semi solid

Question 26 1 Marks

Which compressor dome handles high pressure and high temperature vapour?

A

Semi hermetic reciprocating compressor

B

Open type reciprocating compressor

C

Hermetic reciprocating compressor

D

Hermetic rotary compressor

Question 27 1 Marks

Which components are connected by metering device in vapour compression cycle?

A

Condenser and evaporator

B

Compressor and condenser

C

Evaporator and suction line

D

Compressor and evaporator

Question 28 1 Marks

What is top dead centre in reciprocating compressor cylinder?

A

The piston moves down from the point of cylinder

B

The piston moves up from the point of cylinder

C

The piston stops in cylinder at bottom

D

The piston starts in cylinder at bottom

Question 29 1 Marks

What is the melting temperature of silver
brazing rod?

A

1120 Degree F

B

1200 Degree F

C

1250 Degree F

D

1300 Degree F

Question 30 1 Marks

What is the advantage of using flux in brazing?

A

Over heating

B

Melting tubes

C

Prevent Oxidation

D

Chemical reaction

Question 31 1 Marks

Which components maintain the pressure difference in RAC system?

A

Condenser and filter

B

Evaporator and motor

C

Receiver and condenser

D

Compressor and expansion device

Question 32 1 Marks

What is the working condition of component during defrost cycle in frost free refrigerator?

A

Evaporator fan motor is running

B

Compressor is not running

C

Thermostat cuts off

D

Relay activated

Question 33 1 Marks

What is the temperature maintained in the refrigerator freezer?

A

0 Degree Centigrade

B

- 15 Degree Centigrade

C

- 45 Degree Centigrade

D

- 65 Degree Centigrade

Question 34 1 Marks

What is the advantage of sealed system compared to open type system?

A

Mechanical efficiency is greater

B

Cylinder lubrication is easier

C

Any refrigerant can be used

D

No shaft seal is required

Question 35 1 Marks

Which component defrosts in frost free refrigerator?

A

Bulb

B

Heater

C

Thermostat

D

Capillary tube

Question 36 1 Marks

Which type of evaporator is used in frost free refrigerator?

A

Plate type

B

Wire mesh

C

Finned tube

D

Shell and tube

Question 37 1 Marks

What is the cause for refrigerator door gap at closing position?

A

Uneven floor level

B

Either side gap more

C

Either side gap less

D

Uneven condenser level

Question 38 1 Marks

Which method of refrigeration system is adopted in frost free refrigerator?

A

Vapour compression

B

Vapour absorption

C

Water vapour

D

Evacuating

Question 39 1 Marks

Which component actuates the defrost cycle in frost free refrigerator?

A

Bimetal thermo

B

Defrost heater

C

Timer

D

Relay

Question 40 1 Marks

Where the thermal bulb is fixed in frost free refrigerator?

A

Liquid line

B

Discharge line

C

Last coil of condenser

D

Last coil of evaporator

Question 41 1 Marks

What is the cut out temperature of bimetal thermo in frost free refrigerator?

A

5 Degree Centigrade

B

10 Degree Centigrade

C

20 Degree Centigrade

D

25 Degree Centigrade

Question 42 1 Marks

Which sheet is used to check the tigtness of door gasket of a refrigerator?

A

Rubber

B

Plastic

C

Copper

D

Zinc

Question 43 1 Marks

Which movement of plunger energises the start winding in relay operation?

A

Vertically up

B

Bottom side

C

Vertically down

D

Horizontally left

Question 44 1 Marks

Which component is turned off while defrost heater is energised?

A

Cabinet bulb

B

Evaporator fan

C

Thermostat sensor

D

Over load protector

Question 45 1 Marks

Which device protects the compressor motor from drawing more current?

A

OLP

B

Relay

C

Thermostat

D

Door switch

Question 46 1 Marks

Which component switches ON/OFF the starting winding in RSIR motor?

A

Thermostat

B

Capacitor

C

Relay

D

OLP

Question 47 1 Marks

Which domestic system uses automatic defrost?

A

Frost free refrigerator

B

Conventional refrigerator

C

Split air - conditioner

D

Window air - conditioner

Question 48 1 Marks

How the capacity of refrigerator is expressed?

A

Weightage

B

Tonnage

C

Wattage

D

Litres

Question 49 1 Marks

Which is used to clean the condenser fins of a refrigerator?

A

Painting brush

B

Diluted acid

C

Soap solution

D

Fin comb

Question 50 1 Marks

Which electrical control cuts off heating element in frost free refrigerator?

A

Bimetal thermo

B

Thermostat

C

Relay

D

Timer

Question 51 1 Marks

Where the manually defrosted water is stored in refrigerator?

A

Tray on top of the compressor

B

Bottom of the evaporator

C

Bottom of the condenser

D

Top of the freezer

Question 52 1 Marks

What is the effect of bimetal thermo stucks in ON position in frost free refrigerator?

A

Accumulation of frost

B

More cooling

C

Poor cooling

D

No cooling

Question 53 1 Marks

Which component is replaced to prevent air entering the refrigerator cabinet?

A

Thermostat

B

Door gasket

C

Door paint

D

Door hinges

Question 54 1 Marks

What is the result if discharge reed is broken in open type compressor?

A

Poor pumping

B

More pumping

C

Oil pumping

D

No pumping

Question 55 1 Marks

Which component is used in frost free refrigerator?

A

Plate coil evaporator

B

Liquid receiver

C

Oil separator

D

Timer switch

Question 56 1 Marks

Why frost free model refrigerator takes less freezing time of products?

A

Forced air circulation

B

Natural air circulation

C

Low temperature setting

D

High temperature setting

Question 57 1 Marks

What is the reason if refrigerator runs normally but no cooling effect?

A

Leakage of refrigerant

B

Condenser block

C

Filter block

D

Over charge

Question 58 1 Marks

What is the effect of contamination in refrigeration system?

A

High heating

B

Poor cooling

C

Low pressure

D

Low humidity

Question 59 1 Marks

Which is connected in series with start capacior in motor circuit?

A

Starting winding

B

Common terminal

C

Running Terminal

D

Running winding

Question 60 1 Marks

Which device equalizes the system pressure in frost free refrigerator?

A

Capillary tube

B

Compressor

C

Condenser

D

Evaporator

Question 61 1 Marks

How pressure drop is achieved in capillary tube of refrigeration cycle?

A

The friction between refrigerant and tube

B

The friction between refrigerant and oil

C

The friction between piston and cylinder

D

The friction between belt and pulley

Question 62 1 Marks

What is the advantage of using capillary tube as an expansion device?

A

Temperature balancing is easy

B

Pressure balancing is easy

C

Volume balancing is easy

D

Complicate design

Question 63 1 Marks

Which type of defrosting method is used in frost free refrigerator?

A

Hot water defrosting

B

Manual defrosting

C

Hot gas defrosting

D

Electric defrosting

Question 64 1 Marks

Why the supply air throw is decreased in window AC?

A

Normal RPM of fan motor

B

Clean air filter

C

Refrigerant leaks

D

Frost blocks air circulation

Question 65 1 Marks

Why there is no frosting at the bottom only in plate coil evaporator used with refrigerator?

A

Shortage of refrigerant

B

Oil present in the coil

C

Excess of refrigerant

D

Liquid in the coil

Question 66 1 Marks

What is the type of condenser used in direct cool refrigerator?

A

Fin and tube

B

Shell and tube

C

Wire mesh

D

Tube in tube

Question 67 1 Marks

Which gas is used to flush out the coils of air cooled condenser?

A

Dry nitrogen

B

Pure dry air

C

Oxygen

D

kaksr

Question 68 1 Marks

Which type of condenser is directly placed on water spray and air?

A

Shell and tube condenser

B

Water cooled condenser

C

Evaporative condenser

D

Air cooled condenser

Question 69 1 Marks

What is the remedy for defective heating element in a frost free refrigerator?

A

Repair heater

B

Readjust the heater

C

Replace heater and bimetal thermo

D

Reuse the heater and over load protector

Question 70 1 Marks

What is the reason for frost accumulation in
between fins and tubes of evaporator in frost free
refrigerator?

A

Under charge of refrigerant

B

Over charge of refrigerant

C

Defective fan motor

D

Defective timer

Question 71 1 Marks

Which device meters the amount of refrigerant entering the evaporator in window AC?

A

Accumulator

B

Capillary tube

C

Heat exchanger

D

Finned tube condenser

Question 72 1 Marks

Which evaporator is known as extended surface evaporator?

A

Evaporator tubes

B

Finned evaporator

C

Bare tube evaporator

D

Coiled stake evaporator

Question 73 1 Marks

Which component is connected in series with bimetal thermo in a frost free refrigerator?

A

Blower

B

Door switch

C

Cabinet bulb

D

Defrost heater

Question 74 1 Marks

What is the purpose of chemical spraying on finned condenser?

A

Flush out the condenser tubes

B

Remove the rust on the fins

C

Blow the dust from the fins

D

Correct the bends in fins

Question 75 1 Marks

Which type of condenser is used in window Air conditioner?

A

Natural convection

B

Forced convection

C

Water cooled

D

Evaporative

Question 76 1 Marks

Which type of drier filter is suitable for HFC refrigerants?

A

Molecular sieve type

B

Activated alumina

C

Activated carbon

D

Silica gel

Question 77 1 Marks

What is the physical change of refrigerant in evaporator?

A

Solid to liquid

B

Vapour to solid

C

Liquid to vapour

D

Vapour to liquid

Question 78 1 Marks

Which expansion valve is suitable for constant load operation?

A

King valve

B

Relief valve

C

Low side float valve

D

Automatic expansion valve

Question 79 1 Marks

What is the process of accumulation of ice on the surface of evaporator?

A

Frosting

B

Defrosting

C

Evacuating

D

Melting of frost

Question 80 1 Marks

What are the causes for blockage in
capillary tube?

A

Non condensable gases

B

Moisture and wax from oil

C

Solid particles

D

Over charging of refrigerant

Question 81 1 Marks

Which application uses the capillary tube expansion device?

A

Domestic RAC units

B

Industrial ice plants

C

Commercial AC plants

D

Hospital IAQ systems

Question 82 1 Marks

Which gas is used for flushing blocked capillary tube?

A

Moist air

B

Hydrogen

C

Dry nitrogen

D

Aqua ammonia

Question 83 1 Marks

Where the dehydrator is installed in a refrigeration system?

A

Discharge line

B

Capillary line

C

Suction line

D

Liquid line

Question 84 1 Marks

What is the effect of pressure drop at the inlet of the evaporator?

A

Flashing of liquid refrigerant

B

Freezing of liquid refrigerant

C

Freezing of liquid

D

Boiling of oil

Question 85 1 Marks

Why evaporator of air conditioner has more fins per inch?

A

Increase the air contact

B

Increase the water dripping

C

Decrease the air circulation

D

Produce more ice

Question 86 1 Marks

Which is the constant reference for the working of AEV?

A

Oil temperature

B

Suction pressure

C

Volume expansion

D

Discharge pressure

Question 87 1 Marks

What is the physical state of refrigerant at the outlet of condenser in vapour compression cycle?

A

High pressure vapour

B

High pressure liquid

C

Low pressure liquid

D

Low pressure vapour

Question 88 1 Marks

Which type of expansion device is used in frost free refrigerator?

A

Float valve

B

Capillary tube

C

Automatic expansion valve

D

Thermostatic expansion valve

Question 89 1 Marks

Why frost accumulates in window AC evaporator?

A

Over charge of refrigerant

B

Less charge of refrigerant

C

Capillary chocking

D

Air filter blocked

Question 90 1 Marks

Which type of insulation material is used in modern refrigerators?

A

Saw dust

B

Glass wool

C

Thermocole

D

Poly urethane foam

Question 91 1 Marks

What is the reason for no cooling in a frost
free refrigerator?

A

Defective fan motor

B

Open door switch

C

High watt Cabinet bulb

D

Defective timer

Question 92 1 Marks

Which cooling medium is used to condense the refrigerant vapour in plate and tube condenser?

A

Natural Air

B

Forced Air

C

Water

D

Brine solution

Question 93 1 Marks

What is the remedy for broken bimetal thermo in a frost free refrigerator?

A

Repair the bimetal thermo

B

Reuse the bimetal thermo

C

Replace the bimetal thermo

D

Readjust the bimetal thermo

Question 94 1 Marks

What is the use of dehydrator?

A

Absorb oil

B

Absorb heat

C

Absorb refrigerant

D

Absorb moisture

Question 95 1 Marks

What is the desiccant used in dehydrator of hydrocarbon charged RAC unit?

A

Silica gel

B

Ammonia

C

Sulphur dioxide

D

Calcium chloride

Question 96 1 Marks

Which component is connected in series with defrost heater in a frost free refrigerator?

A

Door switch

B

Cabinet bulb

C

Bimetal thermo

D

Heating element

Question 97 1 Marks

Which is the constant operating condition of TEV?

A

Super heat at suction line point

B

Evaporator pressure at its inlet

C

Enthalpy at the evaporator outlet

D

Entropy at the condenser outlet

Question 98 1 Marks

Which colour is used for painting condenser coil?

A

Green

B

Black

C

Blue

D

Red

Question 99 1 Marks

Which type of evaporator is used in house hold refrigerator?

A

Plate evaporator

B

Tube in tube evaporator

C

Shell and coil evaporator

D

Shell and tube evaporator

Question 100 1 Marks

How much minimum gap is left on either side of the refrigerator from the wall during installation?

A

5 cm

B

10 cm

C

15 cm

D

25 cm

Question 101 1 Marks

Why the capillary tube is preferred as an
expansion device?

A

No system pressure equalising

B

Inexpensive and has no moving parts

C

Expensive and more moving parts

D

Periodical servicing is required

Which two components do the compressor function in vapour absorption system?

Which thermodynamic process the temperature is kept constant?

Which instrument is used to measure atmospheric pressure?

What is the absolute pressure of gas in a cylinder, if gauge reads 135.3 p.s.i?

What is the rate of doing work?

Which factors produce work?

Which condition is maintained for refrigerant in high side of vapour compression system?

Which instrument is used for measuring heat?

What is the purpose of accumulator in a refrigerator?

What is the energy of a body by virtue of its position?

Which law is related to the constant PV at constant T?

What is the equivalent absolute scale for centigrade?

Which component controls the thermostat and defrost heater in frost free refrigerator?

What is the boiling point of pure water in centigrade scale?

Which method is used to connect the swaged joint in copper tubes?

What is the capacity of doing work?

What is the absolute zero temperature in degree centigrade?

What is bottom dead centre in reciprocating compressor cylinder?

What is the atmospheric pressure at sea level?

What is the barometer reading at sea level in Hg column?

Which refrigeration system works on directly by the heat energy?

What is effect of compression process on refrigerant vapour?

What is the unit of heat in M.K.S system?

How the level of heat in a substance is expressed?

What is the physical state of ammonia at condenser inlet in vapour absorption system?

Which compressor dome handles high pressure and high temperature vapour?

Which components are connected by metering device in vapour compression cycle?

What is top dead centre in reciprocating compressor cylinder?

What is the melting temperature of silver brazing rod?

What is the advantage of using flux in brazing?

Which components maintain the pressure difference in RAC system?

What is the working condition of component during defrost cycle in frost free refrigerator?

What is the temperature maintained in the refrigerator freezer?

What is the advantage of sealed system compared to open type system?

Which component defrosts in frost free refrigerator?

Which type of evaporator is used in frost free refrigerator?

What is the cause for refrigerator door gap at closing position?

Which method of refrigeration system is adopted in frost free refrigerator?

Which component actuates the defrost cycle in frost free refrigerator?

Where the thermal bulb is fixed in frost free refrigerator?

What is the cut out temperature of bimetal thermo in frost free refrigerator?

Which sheet is used to check the tigtness of door gasket of a refrigerator?

Which movement of plunger energises the start winding in relay operation?

Which component is turned off while defrost heater is energised?

Which device protects the compressor motor from drawing more current?

Which component switches ON/OFF the starting winding in RSIR motor?

Which domestic system uses automatic defrost?

How the capacity of refrigerator is expressed?

Which is used to clean the condenser fins of a refrigerator?

Which electrical control cuts off heating element in frost free refrigerator?

Where the manually defrosted water is stored in refrigerator?

What is the effect of bimetal thermo stucks in ON position in frost free refrigerator?

Which component is replaced to prevent air entering the refrigerator cabinet?

What is the result if discharge reed is broken in open type compressor?

Which component is used in frost free refrigerator?

Why frost free model refrigerator takes less freezing time of products?

What is the reason if refrigerator runs normally but no cooling effect?

What is the effect of contamination in refrigeration system?

Which is connected in series with start capacior in motor circuit?

Which device equalizes the system pressure in frost free refrigerator?

How pressure drop is achieved in capillary tube of refrigeration cycle?

What is the advantage of using capillary tube as an expansion device?

Which type of defrosting method is used in frost free refrigerator?

Why the supply air throw is decreased in window AC?

Why there is no frosting at the bottom only in plate coil evaporator used with refrigerator?

What is the type of condenser used in direct cool refrigerator?

Which gas is used to flush out the coils of air cooled condenser?

Which type of condenser is directly placed on water spray and air?

What is the remedy for defective heating element in a frost free refrigerator?

What is the reason for frost accumulation in between fins and tubes of evaporator in frost free refrigerator?

Which device meters the amount of refrigerant entering the evaporator in window AC?

Which evaporator is known as extended surface evaporator?

Which component is connected in series with bimetal thermo in a frost free refrigerator?

What is the purpose of chemical spraying on finned condenser?

Which type of condenser is used in window Air conditioner?

Which type of drier filter is suitable for HFC refrigerants?

What is the physical change of refrigerant in evaporator?

Which expansion valve is suitable for constant load operation?

What is the process of accumulation of ice on the surface of evaporator?

Which instrument is used for measuring
heat?

What is the absolute zero temperature in
degree centigrade?

What is the atmospheric pressure at sea
level?

Which refrigeration system works on
directly by the heat energy?

How the level of heat in a substance is
expressed?

What is the melting temperature of silver
brazing rod?

What is the reason for frost accumulation in
between fins and tubes of evaporator in frost free
refrigerator?

What are the causes for blockage in
capillary tube?

What is the reason for no cooling in a frost
free refrigerator?

Why the capillary tube is preferred as an
expansion device?