Quiz Questions

ITI Quiz - 06-May-2026 02:56 PM (ITISKILL68313C)

Q-Paper A-Paper
Question 1 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 2 1 Marks
What is the purpose of air filter?
A
Cool air
B
Circulate air
C
Ensure clean air
D
Improve performance
Question 3 1 Marks
Which component rejects the maximum heat to ambinet air in refrigerator?
A
Expansion valve
B
Compressor
C
Condenser
D
Evaporator
Question 4 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 5 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 6 1 Marks
Which fan is used in condensing unit of ductable split air conditioner?
A
Forward curved fan
B
Centrifugal fan
C
Propeller fan
D
Radial fan
Question 7 1 Marks
What is the effect of improper alignment of machines while installing a central AC plant?
A
Silent operation
B
Excess of wear and tear
C
Less noise and vibration
D
Less power consumption
Question 8 1 Marks
Which is a positive displacement
compressor?
A
Centrifugal compressor
B
Scroll compressor
C
Water pump
D
Oil pump
Question 9 1 Marks
How numerical designations of inorganic refrigerants are assigned?
A
Divide 700 to molecular mass of compound
B
Multiply 700 to molecular mass of compound
C
Adding 700 to molecular mass of compound
D
Subtracting 700 from molecular mass of compound
Question 10 1 Marks
Which electronic component senses the temperature in indoor unit of VRV system?
A
Resistor
B
Thyristor
C
Transistor
D
Thermistor
Question 11 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 12 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 13 1 Marks
What is meant by total pressure in a duct?
A
Velocity pressure - static pressure
B
Static pressure + velocity pressure
C
Velocity pressure + suction pressure
D
Suction pressure + discharge pressure
Question 14 1 Marks
Which type of compressor is used as a vacuum pump?
A
Reciprocating
B
Centrifugal
C
Rotary
D
Scroll
Question 15 1 Marks
Which switch is interlocked to become on if the power isolator is off in package AC?
A
Thermostat
B
Blower motor
C
Crankcase heater
D
Compressor starting
Question 16 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 17 1 Marks
What is the cylinder colour code of R 22 refrigerant?
A
White
B
Green
C
Orchid
D
Orange
Question 18 1 Marks
Which control trips if the expansion valve inlet strainer is blocked in chiller AC plant?
A
Thermostat control
B
Low pressure cut out
C
Oil pressure cut out
D
High pressure cut out
Question 19 1 Marks
What is the wet bulb temperature of air if dry bulb temperature is 35 Degree Centigrade and wet bulb depression is 4 Degree Centigrade?
A
30 Degree Centigrade
B
31 Degree Centigrade
C
32 Degree Centigrade
D
33 Degree Centigrade
Question 20 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 21 1 Marks
Which international agency standardises the numbering system for identifying refrigerants?
A
ASHRAE
B
ISHRAE
C
DW142
D
ISO
Question 22 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 23 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 24 1 Marks
Which instrument is used to measure the velocity pressure of air in ducting system?
A
Nanometer
B
Pitot tube
C
Barometer
D
Bourdeon tube
Question 25 1 Marks
What is the reason for switching contacts get carbonised in package AC electrical wiring?
A
Humidity
B
Quality is bad
C
Loose connections
D
Too tight connection contacts
Question 26 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 27 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 28 1 Marks
What is the unit of electric current?
A
Ampere
B
Farad
C
Ohm
D
Volt
Question 29 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 30 1 Marks
Which compressor capacity is suitable for 2 TR air conditioner?
A
3000 Kcal/h
B
4000 Kcal/h
C
5000 Kcal/h
D
6000 Kcal/h
Question 31 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 32 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 33 1 Marks
What is the category of R 290 refrigerant?
A
Halocarbons
B
Azeotropes
C
Hydrocarbons
D
Organic compounds
Question 34 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 35 1 Marks
Which gas is produced by the chemical reaction of carbide and water?
A
Oxygen
B
Nitrogen
C
Acetylene
D
Carbon dioxide
Question 36 1 Marks
Which gas is used for flushing blocked capillary tube?
A
Moist air
B
Hydrogen
C
Dry nitrogen
D
Aqua ammonia
Question 37 1 Marks
Which part of the working refrigeration system, the non condensable accumulate?
A
Accumulator
B
Top of condenser
C
Evaporator outlet
D
Compressor crankcase
Question 38 1 Marks
Which process is done first in split AC for shifting from one place to another?
A
Flushing
B
Evacuation
C
Pump down
D
Vacuumisation
Question 39 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 40 1 Marks
What is the velocity range of air circulated in car AC?
A
2 - 3 m / sec
B
5 - 7 m / sec
C
7 - 9 m / sec
D
9 - 10 m / sec
Question 41 1 Marks
How many fan motors are used in split AC?
A
Two
B
Five
C
Four
D
Three
Question 42 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 43 1 Marks
How the pressure drop of refrigerant flow is minimised during installation of indoor and outdoor units in ductable split AC?
A
Pipe lines with more joints
B
With more horizontal distance
C
System pipes with minimum bends
D
Install units as far as possible
Question 44 1 Marks
How the indoor unit acts during heating cycle of heat pump?
A
Condenser
B
Evaporator
C
Expansion device
D
Electrical heater
Question 45 1 Marks
What is the cause of high condensing pressure in water cooled condenser?
A
Lack of lubrication
B
Damage condenser fan
C
Low load on evaporator
D
Defective cooling water pump
Question 46 1 Marks
Why the miscibility of refrigerant and oil is preferred in car AC?
A
Lubricate the clutch assembly
B
Lubricate the heat exchangers
C
Circulate oil back to compressor
D
Lubricate the moving parts of TEV
Question 47 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 48 1 Marks
What is the differential of control switch if it cuts in at 29 kg/cm<sup>2</sup> and cuts out at 34 kg/cm<sup>2</sup>?
A
5 kg / cm<sup>2</sup>
B
10 kg / cm<sup>2</sup>
C
15 kg / cm<sup>2</sup>
D
20 kg / cm<sup>2</sup>
Question 49 1 Marks
Which valve is used in capacity control system employing hot gas bypass?
A
Relief valve
B
Safety valve
C
Solenoid valve
D
Reversing valve
Question 50 1 Marks
Which material is used for making disc in energy meter?
A
Aluminium
B
Copper
C
Brass
D
Zinc
Question 51 1 Marks
What is the minimum temperature difference in water required between inlet and outlet of water cooled condenser?
A
5 Degree Centigrade
B
15 Degree Centigrade
C
10 Degree Centigrade
D
20 Degree Centigrade
Question 52 1 Marks
Which instrument is used to measure the total pressure in an air duct?
A
Hygrometer
B
Velocimeter
C
Anemometer
D
Pitot tube manometer
Question 53 1 Marks
What is the human body temperature in Degree Centigrade?
A
17 Degree Centigrade
B
27 Degree Centigrade
C
37 Degree Centigrade
D
47 Degree Centigrade
Question 54 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 55 1 Marks
Which device controls the air flow in
ducting system?
A
Grille
B
Damper
C
Register
D
Diffuser
Question 56 1 Marks
What is the comfortable range of relative humidity (RH) for human beings?
A
30 +/- 5%
B
40 +/- 5%
C
50 +/- 5%
D
60 +/- 5%
Question 57 1 Marks
What is the effect of sludge in car AC?
A
Chokes the orifice of TEV
B
Blocks the orifice of AEV
C
Closes the orifice of TEEV
D
Closes the orifice of capillary
Question 58 1 Marks
Which AC connects the indoor evaporator unit with outdoor condenser unit through a wall hole of 7cm diameter?
A
Split air-conditioner
B
Window air-conditioner
C
Central air-conditioner
D
Industrial air-conditioner
Question 59 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 60 1 Marks
Which material is used for making service valve?
A
Brass
B
Cast iron
C
Aluminium
D
Stainless steel
Question 61 1 Marks
Which gauge is connected to the AC plant system before doing pump down operation?
A
Compound gauge
B
Oil pressure gauge
C
High pressure gauge
D
Water pressure gauge
Question 62 1 Marks
Which components are used in AHU of central AC plant?
A
Blower, Air filter, Evaporator
B
Condenser, Fan, Compressor
C
Evaporator, Compressor, Blower
D
Air filter, Compressor, Condenser
Question 63 1 Marks
Which is the mounting location of evaporator in ductable split unit?
A
Floor mounting
B
Wall mounting
C
Ceiling mounting
D
Roof mounting
Question 64 1 Marks
Why the U trap is provided in water drain line of AHU?
A
Allows air from outside
B
Block dust from outside
C
Prevent entry of foul smell
D
Ensure free flow of drain water
Question 65 1 Marks
Which safety switch deactivates the compressor motor circuit if suction pressure falls below the safe limit in package AC?
A
Selector switch
B
Low pressure switch
C
High pressure switch
D
Dual pressure switch
Question 66 1 Marks
What is the equivalent of one microfarad in farad?
A
10-3 farad
B
10-6 farad
C
10-9 farad
D
10-12 farad
Question 67 1 Marks
Which bearing is used in condenser motor of outdoor unit in ductable multi split air conditioner?
A
Open ball bearing
B
Thrust bearing
C
Sleeve bearing
D
Ball bearing
Question 68 1 Marks
Which is eliminated from the system in
vacuumising process?
A
Humidity
B
Moisture
C
Pressure
D
Temperature
Question 69 1 Marks
Why the temperatures of inlet and outlet water in shell and tube condenser are recorded in log sheet?
A
Study about the plant
B
Judge quality of water
C
Checking the hardness of water
D
Fix descaling time for condenser
Question 70 1 Marks
Which tool is used to straighten the deformed fins of air cooled condenser?
A
Blower
B
Fin comb
C
Wire brush
D
Brass brush
Question 71 1 Marks
Which type of switch is used to control the room air temperature in split AC?
A
Over load protector
B
Thermostat switch
C
Manual switch
D
Thermal relay
Question 72 1 Marks
What is the advantage of using flux in brazing?
A
Over heating
B
Melting tubes
C
Prevent Oxidation
D
Chemical reaction
Question 73 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 74 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 75 1 Marks
Which refrigerant is used in domestic refrigerator?
A
R 22
B
R 32
C
R 134 a
D
R 407 c
Question 76 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 77 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 78 1 Marks
Which type of AC system is operated by VRV system?
A
Package AC
B
Central plant AC
C
Multizone split ACs
D
Indirect ACs
Question 79 1 Marks
What is the advantage of glass fibre ducting?
A
Economical
B
Heavy weight
C
Self insulating
D
High heat transfer
Question 80 1 Marks
What is the reason for intermittent cooling cycle in car AC?
A
Moisture in the system
B
Fully evacuated system
C
Excess of lubricant in receiver
D
Non condensables in the system
Question 81 1 Marks
Which component is used in frost free refrigerator?
A
Plate coil evaporator
B
Liquid receiver
C
Oil separator
D
Timer switch
Question 82 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 83 1 Marks
What is the reason for sweating of water on drier filter?
A
Air filter blocked
B
Partially chocked drier filter
C
More air flows through the evaporator
D
Dust accumulated on condenser
Question 84 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 85 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 86 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 87 1 Marks
Which tool is used for service valve
operations in package AC?
A
Cutting pliers
B
Screw spanner
C
Ratchet key/wrench
D
Double end spanner
Question 88 1 Marks
What is the effect of increased out door temperature in car AC?
A
Compressor runs more time
B
Compressor runs less time
C
Performance remains the same
D
Performance increases
Question 89 1 Marks
Which control opens the compressor motor circuit in the event of continuous overload?
A
Thermostat
B
Fusible plug
C
Bimetal strip
D
Spring loaded relief valve
Question 90 1 Marks
Where the liquid refrigerant is stored in multi split Air-conditioner during pump down operation?
A
Evaporator
B
Condenser
C
Accumulator
D
Liquid receiver
Question 91 1 Marks
Why the crankcase heater is energised for compressor during the shut down period of AC plant?
A
Increase viscosity of crankcase oil
B
Decrease viscosity of crankcase oil
C
Increase miscibility of oil with refrigerant
D
Prevent oil foaming on restarting compressor
Question 92 1 Marks
Which winding has low resistance in resistance start induction run motor?
A
Running winding
B
Starting winding
C
Auxiliary winding
D
Common winding
Question 93 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 94 1 Marks
Which fan motor speed is used with outdoor unit in split AC?
A
Single speed
B
Double speed
C
Triple speed
D
Five speed
Question 95 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 96 1 Marks
What is the function of remote control in split AC?
A
Humidity setting
B
Pressure setting
C
Drain water control
D
Transmits signal to operate AC
Question 97 1 Marks
Which position is safe for storing refrigerant cylinder?
A
Upside down
B
Horizontal
C
Inclined
D
Upright
Question 98 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 99 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 100 1 Marks
1 Which control device is used to maintain the room air temperature?
A
OLP
B
Relay
C
Thermostat
D
Selector switch