Quiz Questions

Question 1 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 2 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 3 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 4 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 5 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 6 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 7 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 8 1 Marks

What is the capacity of doing work?

A

Work

B

Power

C

Force

D

Energy

Question 9 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 10 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 11 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 12 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 13 1 Marks

Which factors produce work?

A

Force and distance

B

Time and distance

C

Force and power

D

Force and time

Question 14 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 15 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 16 1 Marks

Which instrument is used for measuring
heat?

A

Thermometer

B

Anemometer

C

Calorimeter

D

Ammeter

Question 17 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 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 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 20 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 21 1 Marks

Which instrument is used to measure atmospheric pressure?

A

Hygrometer

B

Hydrometer

C

Manometer

D

Barometer

Question 22 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 23 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 24 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 25 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 26 1 Marks

What is the advantage of using flux in brazing?

A

Over heating

B

Melting tubes

C

Prevent Oxidation

D

Chemical reaction

Question 27 1 Marks

What is the equivalent absolute scale for centigrade?

A

Kelvin

B

Celsius

C

Rankine

D

Fahrenheit

Question 28 1 Marks

How the level of heat in a substance is
expressed?

A

Micron

B

Pressure

C

Humidity

D

Temperature

Question 29 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 30 1 Marks

What is the rate of doing work?

A

Duty

B

Force

C

Power

D

Velocity

Question 31 1 Marks

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

A

Thermoheater

B

Defrost timer

C

Relay

D

OLP

Question 32 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 33 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 34 1 Marks

Which component defrosts in frost free refrigerator?

A

Bulb

B

Heater

C

Thermostat

D

Capillary tube

Question 35 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 36 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 37 1 Marks

Which device protects the compressor motor from drawing more current?

A

OLP

B

Relay

C

Thermostat

D

Door switch

Question 38 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 39 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 40 1 Marks

How the capacity of refrigerator is expressed?

A

Weightage

B

Tonnage

C

Wattage

D

Litres

Question 41 1 Marks

What is the effect of contamination in refrigeration system?

A

High heating

B

Poor cooling

C

Low pressure

D

Low humidity

Question 42 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 43 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 44 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 45 1 Marks

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

A

Bimetal thermo

B

Thermostat

C

Relay

D

Timer

Question 46 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 47 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 48 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 49 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 50 1 Marks

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

A

Thermostat

B

Capacitor

C

Relay

D

OLP

Question 51 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 52 1 Marks

Which component actuates the defrost cycle in frost free refrigerator?

A

Bimetal thermo

B

Defrost heater

C

Timer

D

Relay

Question 53 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 54 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 55 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 56 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 57 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 58 1 Marks

Which device equalizes the system pressure in frost free refrigerator?

A

Capillary tube

B

Compressor

C

Condenser

D

Evaporator

Question 59 1 Marks

Which component is used in frost free refrigerator?

A

Plate coil evaporator

B

Liquid receiver

C

Oil separator

D

Timer switch

Question 60 1 Marks

Which domestic system uses automatic defrost?

A

Frost free refrigerator

B

Conventional refrigerator

C

Split air - conditioner

D

Window air - conditioner

Question 61 1 Marks

Which movement of the scroll compresses the low pressure vapour in scroll compressor?

A

Reciprocating

B

Centrifugal

C

Rotating

D

Orbital

Question 62 1 Marks

What is the advantage of a hermetically sealed compressor in refrigerator?

A

Silent operation

B

Easily serviceable

C

Noise is more

D

Cost is high

Question 63 1 Marks

What is the use of a starting capacitor in single phase induction motor?

A

Improve power factor

B

Increase starting torque

C

Decrease starting torque

D

Dis connect starting winding

Question 64 1 Marks

Which valve is closed during compression stroke in reciprocating compressor?

A

Service valve

B

Liquid line valve

C

Discharge valve

D

Suction valve

Question 65 1 Marks

What is the temperature set in thermostat that stops the compressor motor?

A

Cut in

B

Range

C

Cut out

D

Differential

Question 66 1 Marks

Which type of compressor is used for domestic refrigerator?

A

Semi sealed compressor

B

Centrifugal compressor

C

Hermetic compressor

D

Open type compressor

Question 67 1 Marks

Which instrument is used to identify the
terminals of a compressor motor?

A

Ammeter

B

Voltmeter

C

Ohm meter

D

Anemometer

Question 68 1 Marks

Which winding is made of thick wire in single phase induction motor?

A

Starting

B

Running

C

Auxiliary

D

Additional

Question 69 1 Marks

Why the top of dome is hot in a scroll compressor?

A

Discharge plenum is at top

B

Suction super heat is less

C

Suction gas not cooled

D

Undercharged system

Question 70 1 Marks

Which is a positive displacement
compressor?

A

Centrifugal compressor

B

Scroll compressor

C

Water pump

D

Oil pump

Question 71 1 Marks

What is the reason for swash plate compressor failure in car AC?

A

Oil level is low

B

Oil level is medium

C

Thermostat not working

D

Refrigerant charge normal

Question 72 1 Marks

What is the revolving part of induction motor?

A

Stator

B

Rotor

C

Relay

D

Winding

Question 73 1 Marks

Which cooling medium is used to cool the motor of a hermetic reciprocating compressor in AC?

A

Discharge vapour

B

Liquid refrigerant

C

Suction vapour

D

Water

Question 74 1 Marks

Which motor has the least starting
torque?

A

CSIR

B

CSR

C

RSIR

D

PSC

Question 75 1 Marks

Which type of rotor is used in 3 Phase induction motor?

A

Squirrel cage rotor

B

Shaded pole rotor

C

Laminated rotor

D

Solid rotor

Question 76 1 Marks

Which part connects the piston with small end of connecting rod in a reciprocating compressor?

A

Piston pin

B

Piston bolt

C

Piston rings

D

Piston sleeve

Question 77 1 Marks

What is the effect of moist air present inside the hermetic system?

A

Capacity of compressor will increase

B

Less wear and tear in compressor

C

Harmful to the compressor and motor

D

Increase the life of compressor

Question 78 1 Marks

Which is disconnected by centrifugal switch is RSIR motor?

A

Running winding

B

Common winding

C

Starting winding

D

Running capacitor

Question 79 1 Marks

How to change the direction of rotation in
3 Phase induction motor?

A

Change neutral

B

Change all phase

C

Change any two phase

D

Change the winding only

Question 80 1 Marks

Where the refrigerant vapour is compressed in scroll compressor?

A

Fixed and reciprocating scroll

B

Between fixed and orbiting scrolls

C

Crank and connecting rod

D

Eccentric and cylinder

Question 81 1 Marks

What is the formula to find out the
synchronous speed of induction motor?

A

Ns=(150P/f)

B

Ns=(120f/P)

C

Ns=(150f/P)

D

Ns=(120P/f)

Question 82 1 Marks

What is the use of suction baffle in a scroll compressor?

A

Reduce noise of compressor

B

Increase noise of compressor

C

Reduce capacity of compressor

D

Allow liquid to enter into compressor

Question 83 1 Marks

Which motor has the least starting
torque?

A

CSIR

B

CSR

C

RSIR

D

PSC

Question 84 1 Marks

What is the physical condition of refrigerant
in hermetic dome of rotary compressor?

A

LP Liquid

B

HP Liquid

C

HP Vapour

D

LP Vapour

Question 85 1 Marks

Which lubricant oil is used in swash plate of R 134a compressor?

A

Servo 20

B

POE

C

SAE - 40

D

Mineral oil

Question 86 1 Marks

What is the reason for poor compression?

A

Less clearance volume

B

Scratches on the piston surface

C

Lapped valve plate and reed seat

D

Good lubrication on the moving parts

Question 87 1 Marks

Which gas is used for pressure testing the compressor dome?

A

Air

B

Oxygen

C

Nitrogen

D

Refrigerant

Question 88 1 Marks

What is the method of starting a 3 phase slip ring induction motor?

A

With starting relay

B

Using starting capacitor

C

With running capacitor

D

Adding resistance to rotor winding

Question 89 1 Marks

Which winding is made of thin wire in single phase motor?

A

Main

B

Series

C

Starting

D

Running

Question 90 1 Marks

What is the use of capacitor in PSC
operated induction motor?

A

Decrease the starting torque

B

Cancel the starting torque

C

Improve the power factor

D

Decrease the power factor

Question 91 1 Marks

What is the cause for frequent tripping of circuit breaker while starting a single phase motor?

A

Winding open

B

Winding short

C

Motor belt removed

D

No load on the motor

Question 92 1 Marks

How the difference between the
synchronous speed and the actual rotor speed is
specified?

A

Lead

B

Lag

C

Slip

D

Trip

Question 93 1 Marks

Which is used to connect the rotor bars in 3phase squirrel cage induction motor?

A

Screw

B

Welded

C

End ring

D

Nut and bolt

Question 94 1 Marks

Which capacitor is disconnected by relay in capacitor start and induction run motor?

A

Starting capacitor

B

Running capacitor

C

Boosting capacitor

D

Power factor correction capacitor

What is top dead centre in reciprocating compressor cylinder?

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

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

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

What is the absolute zero temperature in degree centigrade?

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

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

What is the capacity of doing work?

What is the melting temperature of silver brazing rod?

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

What is the atmospheric pressure at sea level?

Which compressor dome handles high pressure and high temperature vapour?

Which factors produce work?

Which refrigeration system works on directly by the heat energy?

Which thermodynamic process the temperature is kept constant?

Which instrument is used for measuring heat?

Which components maintain the pressure difference in RAC system?

What is bottom dead centre in reciprocating compressor cylinder?

What is the purpose of accumulator in a refrigerator?

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

Which instrument is used to measure atmospheric pressure?

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

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

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

What is effect of compression process on refrigerant vapour?

What is the advantage of using flux in brazing?

What is the equivalent absolute scale for centigrade?

How the level of heat in a substance is expressed?

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

Where the thermal bulb is fixed in frost free refrigerator?

Where the manually defrosted water is stored in refrigerator?

Which component defrosts in frost free refrigerator?

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

What is the temperature maintained in the refrigerator freezer?

Which device protects the compressor motor from drawing more current?

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

Which component is turned off while defrost heater is energised?

How the capacity of refrigerator is expressed?

What is the effect of contamination in refrigeration system?

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

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

Which type of evaporator is used in frost free refrigerator?

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

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

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

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

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

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

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

Which component actuates the defrost cycle in frost free refrigerator?

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

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

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

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

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

Which device equalizes the system pressure in frost free refrigerator?

Which component is used in frost free refrigerator?

Which domestic system uses automatic defrost?

Which movement of the scroll compresses the low pressure vapour in scroll compressor?

What is the advantage of a hermetically sealed compressor in refrigerator?

What is the use of a starting capacitor in single phase induction motor?

Which valve is closed during compression stroke in reciprocating compressor?

What is the temperature set in thermostat that stops the compressor motor?

Which type of compressor is used for domestic refrigerator?

Which instrument is used to identify the terminals of a compressor motor?

Which winding is made of thick wire in single phase induction motor?

Why the top of dome is hot in a scroll compressor?

Which is a positive displacement compressor?

What is the reason for swash plate compressor failure in car AC?

What is the revolving part of induction motor?

Which cooling medium is used to cool the motor of a hermetic reciprocating compressor in AC?

Which motor has the least starting torque?

Which type of rotor is used in 3 Phase induction motor?

Which part connects the piston with small end of connecting rod in a reciprocating compressor?

What is the effect of moist air present inside the hermetic system?

Which is disconnected by centrifugal switch is RSIR motor?

How to change the direction of rotation in 3 Phase induction motor?

What is the absolute zero temperature in
degree centigrade?

What is the melting temperature of silver
brazing rod?

What is the atmospheric pressure at sea
level?

Which refrigeration system works on
directly by the heat energy?

Which instrument is used for measuring
heat?

How the level of heat in a substance is
expressed?

Which instrument is used to identify the
terminals of a compressor motor?

Which is a positive displacement
compressor?

Which motor has the least starting
torque?

How to change the direction of rotation in
3 Phase induction motor?

What is the formula to find out the
synchronous speed of induction motor?

Which motor has the least starting
torque?

What is the physical condition of refrigerant
in hermetic dome of rotary compressor?

What is the use of capacitor in PSC
operated induction motor?

How the difference between the
synchronous speed and the actual rotor speed is
specified?