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WorksheetsJohnson Controls India Mock Test 02
Total questions: 50
Worksheet time: 50mins
A pump fills a tank in 6 hours. Due to leakage, it takes 8 hours. The leakage alone can empty the tank in:
12 h
24 h
16 h
48 h
The average of five consecutive odd numbers is 27. The smallest number is:
19
21
23
25
A sum doubles in 6 years at simple interest. The annual rate of interest is:
8%
10%
12%
16%
A train running at 72 km/h passes a pole in 10 seconds. Its length is:
150 m
180 m
200 m
120 m
The probability of drawing a red card from a standard deck is:
1/2
1/3
1/4
1/13
The next term in the series 2, 6, 12, 20, 30, ? is:
40
42
44
46
A man spends 60% of his salary and saves Rs. 8,000. His salary is:
Rs. 20,000
Rs. 25,000
Rs. 15,000
Rs. 30,000
If 4 workers complete a task in 10 days, how many are needed to finish in 5 days?
2
4
8
10
A shopkeeper marks an article at Rs. 500, offers 10% discount, and earns 20% profit. The cost price is:
Rs. 350
Rs. 360
Rs. 375
Rs. 400
If logx 64 = 3, then x =
2
4
8
16
The efficiency of an ideal Otto cycle increases with:
Decrease in compression ratio
Increase in compression ratio
Increase in clearance volume
Decrease in temperature
COP of a refrigeration system is defined as:
Work input / Heat rejected
Heat removed / Work input
Work input / Heat absorbed
Heat rejected / Heat absorbed
In a psychrometric chart, the horizontal lines represent:
Constant wet-bulb temp
Constant specific humidity
Constant dry-bulb temp
Constant enthalpy
R-134a is classified as:
CFC
HCFC
HFC
Hydrocarbon
The main function of an expansion valve in a refrigeration cycle is to:
Increase refrigerant pressure
Reduce refrigerant pressure
Increase condenser efficiency
Superheat the refrigerant
ASHRAE stands for:
American Society of Heating, Refrigerating and Air-Conditioning Engineers
Association of Standards for HVAC Engineering
American Standards for Heating and Airflow Regulation Engineers
None of these
In duct design, friction losses are generally expressed in:
Pa/m
N/m²
mm of water per metre
Bar
Which type of fan is most efficient for high-volume, low-pressure HVAC applications?
Axial fan
Forward-curved centrifugal fan
Backward-curved centrifugal fan
Vane axial fan
For a beam under bending, maximum stress occurs at:
Neutral axis
Extreme fibers
Mid-depth
Centre of span
The property of a material to resist plastic deformation is called:
Toughness
Hardness
Elasticity
Malleability
Annealing improves:
Hardness
Ductility
Brittleness
Wear resistance
For fully developed laminar flow in a circular pipe, the velocity profile is:
Parabolic
Uniform
Logarithmic
Triangular
In forced convection, the Nusselt number is a function of:
Reynolds & Prandtl numbers
Mach & Grashof numbers
Fourier number
Only Reynolds number
In a heat exchanger, LMTD is used to:
Calculate heat transfer area
Calculate fluid velocity
Determine material thickness
Measure fouling factor
The standard code TEMA refers to:
Tubular Equipment Manufacturers Association
Thermal Engineering Manufacturers Association
Tube & Evaporator Maintenance Association
None of these
According to fan laws, for a constant impeller diameter, the volume flow rate varies:
Proportional to speed
Proportional to square of speed
Proportional to cube of speed
Inversely to speed
According to fan laws, the power absorbed varies as:
N
N²
N³
1/N
In a vapour compression system, the component that separates liquid from vapour is:
Receiver
Accumulator
Evaporator
Condenser
The psychrometric process involving change in dry-bulb temperature at constant humidity ratio is:
Sensible heating/cooling
Evaporative cooling
Dehumidification
Adiabatic saturation
The most common duct material in commercial HVAC is:
PVC
GI sheet
Aluminium
Copper
The SI unit of electrical resistance is:
Ohm
Volt
Ampere
Henry
Power factor is defined as:
VI
kW/kVA
V/I
kVA/kW
In a DC motor, commutator is used to:
Increase speed
Reverse current direction
Reduce sparking
Control voltage
Slip in an induction motor is:
Ns - Nr / Ns
Nr - Ns / Nr
Ns / Nr
Nr / Ns
Which motor is preferred for constant speed applications?
DC shunt motor
Series motor
Synchronous motor
Universal motor
The main function of a starter in a motor is to:
Increase current
Reduce starting current
Control frequency
Increase torque
Core loss in a transformer consists of:
Copper loss + Hysteresis loss
Hysteresis loss + Eddy current loss
Eddy current loss only
Hysteresis loss only
In a three-phase system, the phase difference between voltages is:
90 deg
120 deg
60 deg
180 deg
Which type of motor is used in refrigerators?
Shaded pole motor
Synchronous motor
Stepper motor
Servo motor
Star-delta starter reduces starting current to:
Half
One-third
One-fourth
One-sixth
The device used to measure temperature in HVAC systems is:
Thermistor
Thermocouple
RTD
All of these
Pressure in refrigeration systems is measured using:
Manometer
Bourdon gauge
Piezoelectric sensor
All of these
The output of a thermocouple is in:
Ohms
Volts
Amperes
Watts
In control systems, PID stands for:
Proportional, Integral, Derivative
Pressure, Input, Displacement
Proportional, Indirect, Direct
None of these
The most common signal standard for HVAC sensors is:
0-5 V
4-20 mA
0-10 V
1-5 V
Orifice plate measures:
Temperature
Flow rate
Pressure
Humidity
Which sensor is used for humidity measurement?
Capacitive
Resistive
Thermal conductivity
All of these
PLC stands for:
Programmable Logic Controller
Process Level Control
Pressure Limit Control
Programmable Level Calculator
In SCADA, 'A' stands for:
Acquisition
Automation
Application
Analysis
Which transducer converts displacement into electrical signal?
LVDT
Thermistor
Strain gauge
Potentiometer
