Quiz Questions

Question 1 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 2 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 3 1 Marks

Which instrument is used for measuring
heat?

A

Thermometer

B

Anemometer

C

Calorimeter

D

Ammeter

Question 4 1 Marks

What is the equivalent absolute scale for centigrade?

A

Kelvin

B

Celsius

C

Rankine

D

Fahrenheit

Question 5 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 6 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 7 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 8 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 9 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 10 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 11 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 12 1 Marks

What is the advantage of using flux in brazing?

A

Over heating

B

Melting tubes

C

Prevent Oxidation

D

Chemical reaction

Question 13 1 Marks

Which instrument is used to measure atmospheric pressure?

A

Hygrometer

B

Hydrometer

C

Manometer

D

Barometer

Question 14 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 15 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 16 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 17 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 18 1 Marks

Which factors produce work?

A

Force and distance

B

Time and distance

C

Force and power

D

Force and time

Question 19 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 20 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 21 1 Marks

Which gas is used for pressure testing the compressor dome?

A

Air

B

Oxygen

C

Nitrogen

D

Refrigerant

Question 22 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 23 1 Marks

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

A

Main

B

Series

C

Starting

D

Running

Question 24 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 25 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 26 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 27 1 Marks

Which motor has the least starting
torque?

A

CSIR

B

CSR

C

RSIR

D

PSC

Question 28 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 29 1 Marks

Which motor has the least starting
torque?

A

CSIR

B

CSR

C

RSIR

D

PSC

Question 30 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 31 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 32 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 33 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 34 1 Marks

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

A

Reciprocating

B

Centrifugal

C

Rotating

D

Orbital

Question 35 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 36 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 37 1 Marks

What is the revolving part of induction motor?

A

Stator

B

Rotor

C

Relay

D

Winding

Question 38 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 39 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 40 1 Marks

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

A

Ammeter

B

Voltmeter

C

Ohm meter

D

Anemometer

Question 41 1 Marks

Which metal is alloyed with zinc to make brass?

A

Iron

B

Copper

C

Bronze

D

Aluminium

Question 42 1 Marks

Which tool is used for trimming the edges of a sheet metal cylinder?

A

Straight snips

B

Bent snips

C

Tube cutter

D

Scissors

Question 43 1 Marks

Which file is used for filing wood?

A

Double cut file

B

Single cut file

C

Rasp cut file

D

Smooth file

Question 44 1 Marks

What is the equivalent of one micron in millimeter?

A

0.0001 mm

B

0.001 mm

C

0.01 mm

D

0.1 mm

Question 45 1 Marks

Which tool is used for bending long sheet metal?

A

Folding bar

B

Bench vice

C

Hand vice

D

Shear

Question 46 1 Marks

Which material is used to clean oil and grease on the floor?

A

Cotton waste

B

Saw dust

C

Water

D

Air

Question 47 1 Marks

Which tool is used for tightening the odd size bolts and nuts?

A

Socket set

B

Nose pliers

C

Ring spanner

D

Adjustable spanner

Question 48 1 Marks

What is the angle of the tip of centre punch?

A

30 Degree

B

60 Degree

C

90 Degree

D

120 Degree

Question 49 1 Marks

What is the least count of a metric micrometer?

A

0.1 mm

B

0.01 mm

C

0.001 mm

D

000.1 mm

Question 50 1 Marks

What is the material composition of a Tin man s solder?

A

50% Tin 50% Zinc

B

50% Tin 50% lead

C

50% Zinc 50% lead

D

50% Tin 50% Bronze

Question 51 1 Marks

Which extinguishes the fire on electrical equipment?

A

Oil

B

Foam

C

Water

D

Halon

Question 52 1 Marks

Which tool is used for bending, seaming and forming of sheet metal?

A

Bench vice

B

Hand vice

C

Stakes

D

Shear

Question 53 1 Marks

What is smothering in fire extinguishing?

A

Pouring of CTC

B

Flashing with dry powder

C

Use water to lower temperature

D

Cutting off oxygen supply to fire

Question 54 1 Marks

Which instrument is used to measure pressure on both high and low side of the system?

A

Pipe manifold

B

Gauge manifold

C

Pressure manifold

D

Instrument manifold

Question 55 1 Marks

What is the name of the caliper having one leg with an adjustable divider point and other leg is bent?

A

Jenny Caliper

B

Inside Caliper

C

Outside caliper

D

Spring joint caliper

Question 56 1 Marks

Which extinguishes the fire of flammable liquids?

A

Water

B

Air

C

CO2

D

Oil

Question 57 1 Marks

Which materials are used to make mallets?

A

Wood, cast iron

B

Wood, rubber

C

Rubber, brass

D

Wood, brass

Question 58 1 Marks

What is starving in extinguishing the fire?

A

Adding fuel

B

Removal of fuel

C

Clearing the hazards

D

Stop the supply of oxygen

Question 59 1 Marks

Which medium is used to extinguish Class - A fire?

A

CO2

B

Foam

C

Water

D

Dry powder

Question 60 1 Marks

Which is the point angle of a twist drill used for zinc alloy?

A

90 Degree

B

100 Degree

C

118 Degree

D

125 Degree

Question 61 1 Marks

What is the remedy for the defective OLP in a window air conditioner?

A

Repair the OLP

B

Replace the OLP

C

Remove the parts

D

Repair the heater element

Question 62 1 Marks

What is the purpose of relay used in window air conditioner?

A

Disconnect the starting capacitor

B

Disconnect the running capacitor

C

Disconnect the fan capacitor

D

Disconnect the winding

Question 63 1 Marks

What is the cooling capacity of 0.5 TR in BTU / hr?

A

6000

B

12000

C

18000

D

24000

Question 64 1 Marks

Which winding of compressor motor is directly connected across voltage relay coil?

A

Main winding

B

Starting winding

C

Running winding

D

Auxiliary winding

Question 65 1 Marks

Which capacitor is connected in series with starting winding of CSR motor during operation?

A

Fan capacitor|

B

Run capacitor

C

Start capacitor

D

No capacitor is connected

Question 66 1 Marks

Which type of expansion valve is used in window air conditioner?

A

Capillary tube

B

Low side float valve

C

Automatic expansion valve

D

Thermostatic expansion valve

Question 67 1 Marks

Which type of evaporator is used in window air conditioner?

A

Bare tube

B

Plate and tube

C

Fins and plate

D

Fins and tube

Question 68 1 Marks

Which relay is used in capacitor start, capacitor run (CSR) compressor motor?

A

Voltage relay

B

Current relay

C

Thermal relay

D

Amperage relay

Question 69 1 Marks

Where the normally closed contacts are internally connected in voltage relay?

A

Across 1 and 5

B

Across 2 and 5

C

Across 1 and 2

D

Across 2 and 4

Question 70 1 Marks

What is the area of room cooled by 1ton window air conditioner?

A

5000 sq.ft

B

2000 sq.ft

C

1000 sq.ft

D

3000 sq.ft

Question 71 1 Marks

What is the purpose of operating the fan motor first and then the compressor motor in Air conditioners?

A

Cool the coils first by fan

B

Cool the compressor by fan

C

Minimise the noise of motors

D

Stop the high starting current by both motors

Question 72 1 Marks

Which device is used to exhaust the room air in window AC?

A

Damper

B

Air filter

C

Filter drier

D

Air washer

Question 73 1 Marks

What is the remedy to remove moisture from the window AC system?

A

Over gas charge in the system

B

Evacuate the system deeply

C

Clean the evaporator fins

D

Clean the condenser fins

Question 74 1 Marks

Which material is used for making fins of condenser in a window air conditioner?

A

Brass

B

Copper

C

Cast iron

D

Aluminium

Question 75 1 Marks

How to neutralise the concentration of leaked ammonia from air

A

Recover ammonia from air

B

Spraying a lot of water

C

Shut down the plant

D

Spray Hydrochloric acid

Question 76 1 Marks

What is the value of running capacitor used for 1.5 TR window air conditioner?

A

36 MFD

B

40 MFD

C

80 MFD

D

100 MFD

Question 77 1 Marks

Which is increased by the fins of condenser tubes in window air conditioner?

A

Heat transfer rate

B

Power consumption

C

Discharge pressure

D

Refrigerant flow rate

Question 78 1 Marks

What is the reason for the compressor does not start but the fan motor works normally in window AC?

A

Defective blower

B

Defective fan motor

C

Defective fan capacitor

D

Defective compressor motor

Question 79 1 Marks

Which safety device is used for compressor motor in window air conditioner?

A

Relay

B

Starting capacitor

C

Running capacitor

D

Over load protector

Question 80 1 Marks

1 Which control device is used to maintain the room air temperature?

A

OLP

B

Relay

C

Thermostat

D

Selector switch

Question 81 1 Marks

What is the name of joint between pieces located at right angle to each other?

A

T - Joint

B

Lap joint

C

Butt joint

D

Grooved joint

Question 82 1 Marks

Which flame is used for welding brass?

A

Wide flame

B

Neutral flame

C

Oxidising flame

D

Carburising flame

Question 83 1 Marks

What is the tool used for holding hot metals?

A

Tongs

B

Spanner

C

Pipe vice

D

Bench vice

Question 84 1 Marks

Which component secures the hose with regulator union in gas welding set?

A

Steel wire

B

Hose clamp

C

Fibre clip

D

Iron chain

Question 85 1 Marks

What is the fault if excess deposit of tiny metal globules formed on the job surface along weld?

A

Incomplete penetration

B

Slag inclusion

C

Blow hole

D

Spatters

Question 86 1 Marks

What is the colour of acetylene hose pipe in oxy - acetylene welding set?

A

Maroon

B

Green

C

Black

D

Red

Question 87 1 Marks

Which method of welding process is suitable to nonferrous dissimilar metals?

A

Cold welding

B

Explosion welding

C

Brazing and bronze welding

D

Ultrasonic method of welding

Question 88 1 Marks

What is the weld test without destroying or breaking the joint?

A

Destructive test

B

Non destructive test

C

Radio graphic test

D

Magnetic test

Question 89 1 Marks

Which valve is closed first while extinguishing flame in gas welding process?

A

Acetylene

B

Hydrogen

C

Oxygen

D

Air

Question 90 1 Marks

Why the acetylene gas is avoided with copper pipe lines or fittings in oxy-acetylene welding set?

A

Copper is expensive

B

Copper is not flexible hose

C

Copper and acetylene form explosive

D

Copper pipe consumes more acetylene

Question 91 1 Marks

Why the filler metal does not melt and flow into the joint in bronze welding of copper?

A

Excess use of flux

B

Due to excess of polished surface

C

Surface coated with oxides or oily material

D

Excessive heating of metal s surface

Question 92 1 Marks

Which group the acetylene gas belongs?

A

HC

B

HFC

C

CFC

D

HCFC

Question 93 1 Marks

What is the ampere setting for 3.5 mm diameter electrode in welding?

A

50 Ampere

B

60 Ampere

C

100 Ampere

D

110 Ampere

Question 94 1 Marks

What is the percentage range of silver in copper to copper pipes brazing rod?

A

20 to 35%

B

35 to 45%

C

45 to 60%

D

60 to 100%

Question 95 1 Marks

What is done after gas charging and pinching the process tube in refrigerator?

A

Flaring

B

Charging

C

Swaging

D

Brazing

Question 96 1 Marks

What is the safety device used during arc welding?

A

Screw clamp

B

Hand screen

C

Electrode holder

D

Lugs for welding

Question 97 1 Marks

How the cylinders of gas welding set are secured in trolley?

A

By cable

B

Using chain

C

Tightened with rope

D

Tied up with belt

Question 98 1 Marks

What is the colour of oxygen hose pipe in oxy - acetylene welding set?

A

Maroon

B

Green

C

Black

D

Red

Question 99 1 Marks

Which is the welding method if the filler rod only is fused?

A

Non fusion

B

Pressure

C

Fusion

D

Forge

Question 100 1 Marks

What is applied to find the leakage on acetylene gas connection?

A

Soap bubbles

B

Halide torch

C

LPG torch

D

By smell

Question 101 1 Marks

What is the reason for filter drier sweating in refrigerator?

A

Nitrogen in the system

B

Moisture in the system

C

Oxygen in the system

D

Oil in the system

Question 102 1 Marks

Which gas is used for pressurising and testing leakage of RAC system?

A

O2

B

N2

C

O3

D

SO2

Question 103 1 Marks

What is the resistance level of start winding in a refrigerator s compressor motor?

A

Medium resistance

B

High resistance

C

Zero resistance

D

Low resistance

Question 104 1 Marks

Which type of compressor is used as a vacuum pump?

A

Reciprocating

B

Centrifugal

C

Rotary

D

Scroll

Question 105 1 Marks

Which material is used to make the evaporator of refrigerator?

A

Galvanised iron

B

Stainless steel

C

Aluminium

D

Brass

Question 106 1 Marks

How does the evaporator frost affect the sub zero temperature thermally in refrigerator?

A

As conductor

B

As insulator

C

As convector

D

As radiator

Question 107 1 Marks

What is the function of refrigerant fluid in a refrigerator?

A

Releases heat inside the cabinet

B

Absorbs heat from inside the cabinet

C

Absorbs heat from outside the cabinet

D

Absorbs heat from bottom side cabinet

Question 108 1 Marks

What is the name of heat carrying medium in vapour compression system?

A

Air

B

Water

C

Liquid

D

Refrigerant

Question 109 1 Marks

What is the fault in compressor motor if there is electrical continuity between the dome and motor terminal?

A

Shorted run winding

B

Open common terminal

C

Shorted start winding

D

Grounded compressor motor

Question 110 1 Marks

Which refrigerant property is desirable for V.C system?

A

Low boiling point

B

Corrosive to metals

C

Low latent heat valve

D

Low Dielectric strength

Question 111 1 Marks

Which part of the refrigerator cools the liquid refrigerant in capillary tube?

A

Discharge line

B

Suction line

C

Condenser

D

Evaporator

Question 112 1 Marks

Which type of motor drive is used in hermetic compressor in refrigerator?

A

Belt drive

B

Gear drive

C

Direct drive

D

Push drive

Question 113 1 Marks

Which refrigerant blend is highly flammable?

A

HCFC

B

HFC

C

CFC

D

HC

Question 114 1 Marks

Which method is used to check the leakage of hydro fluoro carbon refrigerants?

A

Electric torch

B

Litmus paper

C

Sulphur candles

D

Electronic leak detector

Question 115 1 Marks

Which refrigerant is used in domestic refrigerator?

A

R 22

B

R 32

C

R 134 a

D

R 407 c

Question 116 1 Marks

Which component absorbs the maximum heat from the cabinet materials in frost free refrigerator?

A

Condenser

B

Evaporator

C

Compressor

D

Expansion valve

Question 117 1 Marks

Which refrigerant is highly flammable?

A

HC - Hydro carbon

B

HFC - Hydro fluoro carbon

C

CFC - Chloro fluoro carbon

D

HCFC - Hydro chloro fluoro carbon

Question 118 1 Marks

What is the minimum distance to be maintained between the wall and refrigerator condenser?

A

13 cm

B

15 cm

C

18 cm

D

22 cm

Question 119 1 Marks

What is ensured before removing a leaky evaporator in a refrigerator?

A

Recharge refrigerant to the system

B

Check the drain tray of evaporator

C

Removal of the thermostat sensor

D

Pressurize the system with refrigerant

Question 120 1 Marks

Which two tubes act as heat exchanger in a refrigerator?

A

Suction and charging tube

B

Discharge and suction tube

C

Capillary and suction tube

D

Discharge and capillary tube

Question 121 1 Marks

What is the method of converting AC to DC
power supply with two diodes and a step down
transformer?

A

Bridge rectifier

B

Full wave rectifier

C

Half wave rectifier

D

Medium wave rectifier

Question 122 1 Marks

What is the process involved for converting AC to DC power supply?

A

Inversion

B

Regulation

C

Convection

D

Rectification

Question 123 1 Marks

Which material is used for making ICs?

A

Silicon

B

Carbon

C

Platinum

D

Mild steel

Question 124 1 Marks

Which electronic component is the voltage regulator?

A

Zener diode

B

Transistor

C

Triac

D

Diac

Question 125 1 Marks

What is the name of electronic
circuit?

A

Bridge rectifier

B

Half wave rectifier

C

Full wave rectifier

D

Quarter wave rectifier

Question 126 1 Marks

What is the reverse break down voltage range of zener diode?

A

0.1 to 0.5 volt

B

0.5 to 1 volt

C

3 to 18 volt

D

1 to 3 volt

Question 127 1 Marks

What is the unit of inductance?

A

Ohm

B

Henry

C

Farad

D

Ampere

Question 128 1 Marks

How many diodes are required for making a
bridge rectifier circuit?

A

One

B

Two

C

Four

D

Three

Question 129 1 Marks

Which application uses the digital
ICs?

A

Amplifier

B

Logic gates

C

Tuned circuits

D

Voltage regulator

Question 130 1 Marks

Which material is used for making zener diode?

A

Lead

B

Silicon

C

Titanium

D

Platinum

Question 131 1 Marks

What is the unit of capacitance used with single phase induction motors in domestic RAC system?

A

Kilo ohm

B

Microfarad

C

Milli henry

D

Milli ampere

Question 132 1 Marks

Which semiconductor material is used to make diodes?

A

Steel

B

Silicon

C

Copper

D

Aluminium

Question 133 1 Marks

What are the active components used in electronic circuits?

A

Transformers and inductors

B

Transistors, diodes and SCRs

C

Semi conductors and transformers

D

Resistors, capacitors and inductors

Question 134 1 Marks

Which type of diode is used for communication circuits?

A

Signal diode

B

Zener diode

C

Rectifier diode

D

Switching diode

Question 135 1 Marks

What are the passive components used in
electronic circuits?

A

Resistors, capacitors and inductors

B

Transformers and semiconductors

C

Semi conductors and transistors

D

Transistors, diodes and SCRs

Question 136 1 Marks

Which component is used as a switching device in electronic circuit?

A

SCR

B

Diode

C

Capacitor

D

Zener diode

Question 137 1 Marks

What is the name of active component used in electronic circuit?

A

Transistor

B

TRIAC

C

DIAC

D

SCR

Question 138 1 Marks

Which device maintains a constant DC output?

A

Load regulators

B

Rectifier circuits

C

Current limiters

D

Voltage regulators

Question 139 1 Marks

How many terminals are there in a Silicon Controlled Rectifier (SCR)?

A

One

B

Two

C

Four

D

Three

Question 140 1 Marks

How the maximum reverse voltage across the diode is termed in reverse biased condition?

A

Diode voltage

B

Ripple frequency

C

Peak inverse voltage

D

Peak rectification voltage

Question 141 1 Marks

What is the effect of pouring water on electrodes resistance in earth pit?

A

Decreases

B

Increases

C

Equalises

D

Remains same

Question 142 1 Marks

Which property limits the flow of electrons in an electrical circuit?

A

Voltage

B

Current

C

Resistance

D

Conductance

Question 143 1 Marks

How electrons flow in a battery circuit?

A

Phase to earth

B

Phase to neutral

C

Positive to negative polarity

D

Negative polarity to positive polarity

Question 144 1 Marks

Which power supply has the fixed polarity?

A

Direct current

B

Signal voltage

C

Signal ripples

D

Alternating current

Question 145 1 Marks

Which type of 1-? motor has high starting torque?

A

Permanent capacitor

B

Resistance start induction run

C

Capacitor start and capacitor run

D

Induction start and induction run

Question 146 1 Marks

Which tool is used for skinning the insulation of cables and cleaning the wire surface?

A

Hacksaw

B

Firmer chisel

C

Electrician's knife

D

Combination pliers

Question 147 1 Marks

What is the condition of compressor motor if Ohm meter reads infinity across common and start terminals?

A

Running winding open

B

Starting winding open

C

Starting winding shorted

D

Running winding shorted

Question 148 1 Marks

What is the supply voltage if a current of 2 ampere flows through 10 Ohm resistor in a circuit?

A

20 Volt

B

45 Volt

C

55 Volt

D

65 Volt

Question 149 1 Marks

Which meter indicates the true power directly in an electrical circuit?

A

Ammeter

B

Ohm meter

C

Watt meter

D

Volt meter

Question 150 1 Marks

What is the unit of capacitance?

A

Volt

B

Ampere

C

Farad

D

Coulomb

Question 151 1 Marks

What is the unit of electrical energy?

A

Volt

B

Watt

C

Ampere

D

Kilo watt hour

Question 152 1 Marks

Which material is used for making disc in energy meter?

A

Aluminium

B

Copper

C

Brass

D

Zinc

Question 153 1 Marks

Which winding has more inductance in refrigerator compressor motor?

A

Run

B

Start

C

Common

D

Start and common

Question 154 1 Marks

Which law relates to voltage, current and resistance in an electrical circuit?

A

Ohm s law

B

Lenz s law

C

Newton s law

D

Faraday s law

Question 155 1 Marks

Which joint is made in either single or multi - strand conductors?

A

Rat tail joint

B

Scarfed joint

C

Britannia joint

D

Western union joint

Question 156 1 Marks

What is the load resistance in an electrical circuit, if current, I = 2 amp and supply, V = 10 volt?

A

2 Ohms

B

3 Ohms

C

4 Ohms

D

5 Ohms

Question 157 1 Marks

Which is the common terminal while Ohm meter reads AB = 10 Ohm, AC = 15 Ohm and BC = 25 Ohm if the motor terminals are A, B and C?

A

Terminal A

B

Terminal B

C

Terminal C

D

Earth Terminal

Question 158 1 Marks

What is the total resistance if two resistors R1 and R2 are connected in series?

A

(R1 - R2) Ohms

B

(R1 + R2) Ohms

C

(R1 x R2) Ohms

D

(R1 / R2) Ohms

Question 159 1 Marks

What is the unit of electric current?

A

Ampere

B

Farad

C

Ohm

D

Volt

Question 160 1 Marks

What is the rotor speed with respect to stator field speed in an induction motor?

A

Less than the stator speed

B

More than the stator speed

C

Equal to the stator speed

D

More than the fly wheel

Question 161 1 Marks

Which gas is universally taken as the basic reference for GWP?

A

SO2

B

CO2

C

NH3

D

AIR

Question 162 1 Marks

What does the number 4 of R 134a indicate?

A

Number of hydrogen atoms

B

Number of chlorine atoms

C

Number of carbon atoms

D

Number of fluorine atoms

Question 163 1 Marks

What is the category of R 290 refrigerant?

A

Halocarbons

B

Azeotropes

C

Hydrocarbons

D

Organic compounds

Question 164 1 Marks

Which substance absorbs heat and directly changes its state from solid to vapour?

A

Ice

B

Dry ice

C

Primary refrigerants

D

Secondary refrigerants

Question 165 1 Marks

Which is the numerical designation of ammonia refrigerant?

A

700 + ( Molecular mass of NH3) = 717

B

700 + (Molecular mass of NH3) = 718

C

700 + (Molecular mass of NH3) = 719

D

700 + (Molecular mass of NH 3) = 720

Question 166 1 Marks

Which is the green house gas?

A

Oxygen of atmospheric air

B

Chlorofluoro carbon in air

C

Helium of atmospheric air

D

Neon of atmospheric air

Question 167 1 Marks

Which property is desirable for an ideal refrigerant?

A

High boiling point

B

High freezing point

C

High specify volume

D

High latent heat value

Question 168 1 Marks

Which is the inorganic refrigerant?

A

R 170

B

R 500

C

R 630

D

R 717

Question 169 1 Marks

What type of heat is absorbed by primary refrigerant?

A

Total heat

B

Latent heat

C

Specific heat

D

Sensible heat

Question 170 1 Marks

Which type of insulating material is used for making ice box to cool beverages?

A

Tar felt

B

Glass wool

C

Fibre glass

D

Thermocole

Question 171 1 Marks

What is the effect of releasing HFC refrigerants to the atmosphere?

A

Increase global warming potential

B

Increase ozone depleting potential

C

Decrease green house effect

D

Improve water pollution

Question 172 1 Marks

How the refrigerants are classified based on heat absorption by latent and sensible heat?

A

Primary and secondary

B

Organic and inorganic

C

Zeotropic and azeotropic

D

Halocarbons and hydrocarbons

Question 173 1 Marks

How to prevent the small pieces of glass wool affecting the eyes?

A

Wearing goggles

B

Wearing gloves

C

Using mask

D

Using shoes

Question 174 1 Marks

Where does the ozone layer exist in atmosphere?

A

Mesosphere

B

Stratosphere

C

Ionosphere

D

Exosphere

Question 175 1 Marks

Why universal numbering system is adopted for different refrigerants?

A

Identifying the refrigerant's names

B

Mixing the lubricant combination

C

Fixing the drier combination

D

Identify the systems

Question 176 1 Marks

How many hydrogen atoms are present in R 134a?

A

One

B

Two

C

Four

D

Three

Question 177 1 Marks

What is the cylinder colour code of R 22 refrigerant?

A

White

B

Green

C

Orchid

D

Orange

Question 178 1 Marks

Which is the effective method for refrigerant recovery?

A

Condensing unit

B

Charge migration

C

Push pull recovery

D

Use of system's compressor

Question 179 1 Marks

Which refrigerant is used in vapour compression cycle?

A

Secondary refrigerant

B

Primary refrigerant

C

Brine solution

D

Water

Question 180 1 Marks

What is the name of process that changes the used refrigerant to new product?

A

Recover

B

Recycle

C

Reclaim

D

Manufacture

Question 181 1 Marks

What is the value of starting capacitor used for 1TR window air conditioner?

A

40 MFD

B

60 MFD

C

80 MFD

D

100 MFD

Question 182 1 Marks

What is the value of starting capacitor used for 1.5TR capacity window air conditioner?

A

40 to 60 MFD

B

80 to 100 MFD

C

130 to 150 MFD

D

150 to 160 MFD

Question 183 1 Marks

What is the cooling capacity of 1 TR in K Cal / hr?

A

3000

B

4000

C

5000

D

6000

Question 184 1 Marks

Where the filter drier is installed in window AC refrigerant circuit?

A

Discharge line

B

Suction line

C

Service line

D

Liquid line

Question 185 1 Marks

What is the reason for Compressor does not start ?

A

Defective fresh air damper

B

Defective oscillation motor

C

Defective fan motor

D

Defective OLP

Question 186 1 Marks

Which winding has high inductance value in CSR compressor motor?

A

Common winding

B

Running winding

C

Starting winding

D

Auxiliary winding

Question 187 1 Marks

Which type of compressor is used in window air conditioner?

A

Belt drive

B

Open type

C

Sealed type

D

Swash plate

Question 188 1 Marks

What is the reason for the compressor motor burn out in a window air conditioner?

A

Defective fan capacitor

B

Defective fan motor

C

Defective blower

D

Defective OLP

Question 189 1 Marks

Which type of fan motor is used in window air conditioner?

A

Three phase single shaft motor

B

Single phase single shaft motor

C

Three phase double end shaft motor

D

Single phase double end shaft motor

Question 190 1 Marks

What is the capacity of compressor motor used in 1Ton window air conditioner?

A

0.50 HP

B

0.75 HP

C

0.95 HP

D

1.00 HP

Question 191 1 Marks

Where the relay coil is internally connected in voltage relay?

A

Across 1 and 2

B

Across 5 and 1

C

Across 5 and 2

D

Across 2 and 4

Question 192 1 Marks

What is the effect of sensing higher
temperature by thermistor NTC?

A

Resistance increases

B

Resistance decreases

C

Resistance becomes zero

D

Resistance becomes infinity

Question 193 1 Marks

Which capacity of fan motor is used in 1Ton window air conditioner?

A

1/5 HP

B

1/10 HP

C

1/16 HP

D

1/20 HP

Question 194 1 Marks

What is the reason for excessive frost on evaporator coil in window AC?

A

Evaporator fins not blocked by dust

B

Blower rotating at higher speed

C

Air filter blocked completely

D

More air circulation in evaporator

Question 195 1 Marks

Which stabilizer capacity is used for 1 Ton window air conditioner?

A

2 KVA

B

3 KVA

C

4 KVA

D

5 KVA

Question 196 1 Marks

Which is indicated by the arrow mark on filter drier component?

A

Flow direction of air

B

Position of capillary tube

C

Flow direction of refrigerant

D

Arrangement of desiccant and filter

Question 197 1 Marks

Which type of condenser is used in window air conditioner?

A

Fins and tube

B

Plate and tube

C

Plate and coil

D

Bare tube

Question 198 1 Marks

What is the reason for Very high condenser temperature in a window air conditioner?

A

Water splashes condenser

B

More air flows into the condenser

C

Fan motor working in good condition

D

Dust accumulated in the condenser fins

Question 199 1 Marks

What is the cause of reduced supply air throw though air filter is clean in window AC?

A

No frost in the evaporator

B

Frost accumulated in the evaporator

C

Dust accumulated in the condenser

D

No dust accumulated in the evaporator

Question 200 1 Marks

Which part of window AC removes dust particles from the room air?

A

Strainer

B

Air filter

C

Filter drier

D

Dehydrator

What is effect of compression process on refrigerant vapour?

What is the absolute zero temperature in degree centigrade?

Which instrument is used for measuring heat?

What is the equivalent absolute scale for centigrade?

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

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

Which thermodynamic process the temperature is kept constant?

Which refrigeration system works on directly by the heat energy?

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

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

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

What is the advantage of using flux in brazing?

Which instrument is used to measure atmospheric pressure?

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

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

Which components maintain the pressure difference in RAC system?

What is the purpose of accumulator in a refrigerator?

Which factors produce work?

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

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

Which gas is used for pressure testing the compressor dome?

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

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

Which valve is closed during compression stroke in reciprocating compressor?

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

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

Which motor has the least starting torque?

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

Which motor has the least starting torque?

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

Which type of compressor is used for domestic refrigerator?

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

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

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

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

What is the reason for poor compression?

What is the revolving part of induction motor?

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

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

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

Which metal is alloyed with zinc to make brass?

Which tool is used for trimming the edges of a sheet metal cylinder?

Which file is used for filing wood?

What is the equivalent of one micron in millimeter?

Which tool is used for bending long sheet metal?

Which material is used to clean oil and grease on the floor?

Which tool is used for tightening the odd size bolts and nuts?

What is the angle of the tip of centre punch?

What is the least count of a metric micrometer?

What is the material composition of a Tin man s solder?

Which extinguishes the fire on electrical equipment?

Which tool is used for bending, seaming and forming of sheet metal?

What is smothering in fire extinguishing?

Which instrument is used to measure pressure on both high and low side of the system?

What is the name of the caliper having one leg with an adjustable divider point and other leg is bent?

Which extinguishes the fire of flammable liquids?

Which materials are used to make mallets?

What is starving in extinguishing the fire?

Which medium is used to extinguish Class - A fire?

Which is the point angle of a twist drill used for zinc alloy?

What is the remedy for the defective OLP in a window air conditioner?

What is the purpose of relay used in window air conditioner?

What is the cooling capacity of 0.5 TR in BTU / hr?

Which winding of compressor motor is directly connected across voltage relay coil?

Which capacitor is connected in series with starting winding of CSR motor during operation?

Which type of expansion valve is used in window air conditioner?

Which type of evaporator is used in window air conditioner?

Which relay is used in capacitor start, capacitor run (CSR) compressor motor?

Where the normally closed contacts are internally connected in voltage relay?

What is the area of room cooled by 1ton window air conditioner?

What is the purpose of operating the fan motor first and then the compressor motor in Air conditioners?

Which device is used to exhaust the room air in window AC?

What is the remedy to remove moisture from the window AC system?

Which material is used for making fins of condenser in a window air conditioner?

How to neutralise the concentration of leaked ammonia from air

What is the value of running capacitor used for 1.5 TR window air conditioner?

Which is increased by the fins of condenser tubes in window air conditioner?

What is the reason for the compressor does not start but the fan motor works normally in window AC?

Which safety device is used for compressor motor in window air conditioner?

What is the absolute zero temperature in
degree centigrade?

Which instrument is used for measuring
heat?

Which refrigeration system works on
directly by the heat energy?

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

Which motor has the least starting
torque?

Which motor has the least starting
torque?

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

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

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

What is the method of converting AC to DC
power supply with two diodes and a step down
transformer?

What is the name of electronic
circuit?

How many diodes are required for making a
bridge rectifier circuit?

Which application uses the digital
ICs?

What are the passive components used in
electronic circuits?