WorksheetsJohnson Controls India Assessment Test 05
Total questions: 50
Worksheet time: 50mins
The least number divisible by 12, 15 and 20 is:
120
150
180
240
The difference between simple interest and compound interest on ₹10,000 for 2 years at 10% is:
₹100
₹200
₹300
₹400
If A’s salary is 25% more than B’s, then B’s salary is what percent less than A’s?
15%
20%
22%
25%
The ratio 2:3 is equivalent to:
4:6
6:8
8:12
Both a & c
The average of 5 consecutive even numbers is 36. The largest number is:
38
40
42
44
If 3 workers can complete a task in 12 days, how many workers are required to finish it in 4 days?
8
9
10
12
The probability of getting a sum of 7 when two dice are thrown is:
1/12
1/6
1/9
1/18
A train crosses a man in 15 sec and a 300 m long platform in 45 sec. The train length is:
150 m
200 m
250 m
300 m
The next term of the series: 7, 14, 28, 56, ?
84
100
112
128
If cost price = ₹250 and profit = 20%, selling price is:
₹275
₹280
₹300
₹320
Which material is commonly used for fuse wire?
Copper
Silver
Tin-lead alloy
Aluminum
The frequency of supply in the USA is:
25 Hz
50 Hz
60 Hz
75 Hz
The unit of inductance is:
Farad
Henry
Weber
Tesla
A synchronous generator always runs at:
Variable speed
Constant speed
Above synchronous speed
Below synchronous speed
A diode allows current in:
Both directions
Only forward direction
Only reverse direction
None
Which motor is preferred for elevators?
Synchronous motor
Stepper motor
DC series motor
Induction motor
The color code of a 220 Ω resistor with ±5% tolerance is:
Red, Red, Brown, Gold
Red, Red, Black, Gold
Red, Red, Brown, Silver
Red, Black, Red, Gold
In a capacitor, energy is stored in the form of:
Current
Magnetic field
Electric field
Resistance
Which rectifier has the highest efficiency?
Half-wave
Full-wave
Bridge
Both b & c
Power factor close to unity is desirable because:
Reduces current and losses
Increases current
Decreases efficiency
Increases losses
A thermistor is used for:
Pressure measurement
Temperature measurement
Flow measurement
Level measurement
The accuracy of an instrument is defined as:
Closeness to true value
Repeatability
Sensitivity
Resolution
Potentiometer is used for measuring:
Voltage
Current
Resistance
Power
The principle of an LVDT is based on:
Capacitance variation
Inductance variation
Resistance variation
Magnetic reluctance
Which flowmeter works on Bernoulli’s principle?
Rotameter
Orifice meter
Turbine meter
Electromagnetic meter
The output of a thermocouple is:
Resistance
Current
Voltage
Capacitance
pH meter works on the principle of:
Potential difference measurement
Resistance measurement
Inductance measurement
Optical measurement
A strain gauge changes:
Resistance with strain
Voltage with strain
Capacitance with strain
Inductance with strain
In measurement systems, span is:
Difference between max & min range
Minimum input value
Maximum input value
Error limit
An encoder converts:
Linear displacement into voltage
Mechanical motion into digital signals
Force into current
Voltage into frequency
The unit of thermal conductivity is:
W/mK
W/m²K
J/kgK
kJ/kg
In HVAC, the term 'ton of refrigeration' is equal to:
210 kJ/hr
12,000 BTU/hr
1000 kcal/hr
1 kW/hr
The refrigerant R-1234yf belongs to:
CFC group
HFC group
HFO group
Ammonia group
The evaporator in a refrigeration cycle:
Rejects heat
Absorbs heat
Compresses gas
Expands gas
Which heat exchanger arrangement is most efficient?
Parallel flow
Counter flow
Cross flow
Multi-pass
The purpose of a cooling tower is:
Absorb heat from refrigerant
Reject heat from condenser water
Store chilled water
Control humidity
Which compressor is used in very large chillers?
Screw
Scroll
Centrifugal
Reciprocating
Newton’s law of cooling governs:
Conduction
Convection
Radiation
Evaporation
Which refrigerant has zero ODP?
R-22
R-12
R-134a
R-123
The LMTD method is applied in:
Heat exchanger analysis
Boiler design
Pump efficiency
Fan power calculation
COP of a refrigeration system is always:
>1
1
Psychrometric chart is used to study:
Refrigerant properties
Air properties
Condenser performance
Heat exchanger design
In HVAC, VRF stands for:
Variable Refrigerant Flow
Ventilation Return Flow
Variable Resistance Factor
Vapor Return Facility
Surge in centrifugal compressors is:
Stable flow
Reversal of flow and instability
Increase in pressure ratio
Maximum efficiency condition
In mechanical systems, enthalpy is:
Heat + Work
Internal energy + PV
Kinetic energy
Potential energy
The coefficient of performance of an ideal Carnot refrigerator depends on:
Pressure ratio
Temperature limits
Refrigerant type
Compressor size
The main advantage of absorption chiller is:
Uses waste heat instead of electricity
Higher COP than vapor compression
Low initial cost
Compact design
Which international standard is related to HVAC testing & rating?
ISO 14000
AHRI standards
IEEE 519
ASTM A36
Which component regulates refrigerant expansion in a vapor compression cycle?
Condenser
Evaporator
Expansion valve
Compressor
In an HVAC system, economizers are used to:
Reduce energy consumption by using outside air cooling
Increase refrigerant charge
Store excess condensate
Control compressor surge
