[2][2] ።:
Here is the list of questions with all choices (A-D) and the correct answers marked:
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1. What is the device used to measure frequency counter above the audio range?
- A. Electronics frequency
- B. Frequency counter
- C. Bolometer
- D. Cavity wave meter
Correct Answer: B. Frequency counter
2. Which one of the following affects conductor resistivity?
- A. Current
- B. Temperature
- C. Composition
- D. Pressure
Correct Answer: B. Temperature
3. Which one of the following is the property of dielectric materials?
- A. Ferroelectric meter
- B. Insulating material
- C. Magnetic material
- D. Semiconducting material
Correct Answer: B. Insulating material
4. What curve is plotted by giving known inputs to an instrument and obtaining corresponding outputs?
- A. Sensitivity curve
- B. Calibration curve
- C. Characteristics curve
- D. Accuracy curve
Correct Answer: B. Calibration curve
5. Which power electronics device possesses a triple purpose as a phase control, inverter, and
converter?
- A. Zener diode
- B. Transistor
- C. Diode
- D. Thyristor
Correct Answer: D. Thyristor
6. Which IC has more than 1000 gates?
- A. SSI
- B. LSI
- C. VLSI
- D. ULSI
Correct Answer: C. VLSI
7. Why are the frequencies of primary and secondary voltage equal in a transformer?
- A. The open circuit loss is average
- B. The hysteresis loss is minimum and eddy current losses
- C. The induction system acts by the same voltage
- D. The magnetic loss is maximum
Correct Answer: C. The induction system acts by the same voltage
8. Which one is the best representing model of the instrumentation process?
- A. Physical world – signal processing – measuring – sensing element
- B. Physical world – sensing element – signal conditioning – signal processing
- C. Signal conditioning – signal processing – sensor – measuring
Correct Answer: B. Physical world – sensing element – signal conditioning – signal processing
9. What is proposed to be gained from the combination of load torque mechanical to equal?
- A. To specify capacitive power
- B. To gain the correct size of current
- C. To understand the type of electric motor
- D. To make a change of rotation
Correct Answer: C. To understand the type of electric motor
10. On-off control is also called as:
- A. One position control
- B. Two position control
- C. Four position control
- D. Half position control
Correct Answer: B. Two position control
11. In which stage does the measurement system come in contact with the measured quantity?
- A. Transducer stage
- B. Signal processor stage
- C. Output stage
- D. Production stage
Correct Answer: A. Transducer stage
12. The term given to programs stored in ROMs or in programmable devices which permanently keep
their stored information is:
- A. Hardware
- B. Software
- C. Firmware
- D. Universal serial bus
Correct Answer: C. Firmware
13. Which one is a passive sensor?
- A. Thermocouple
- B. Thermistor
- C. Strain gauge
- D. Silicon
Correct Answer: C. Strain gauge
14. The region between the limits within which a quantity is measured, received, or transmitted,
expressed by stating the lower and upper range values is:
- A. Instrument range
- B. Calibration range
- C. Zero error
- D. Field standard
Correct Answer: A. Instrument range
15. If there are 3 identical resistors connected in parallel, the total resistance will be:
- A. 3 times each individual resistor
- B. 2/3 times each individual resistor
- C. 1/3 times each individual resistor
- D. 4/3 times each individual resistor
Correct Answer: C. 1/3 times each individual resistor
16. The responsible person to maintain the quality of work performed by a work team is:
- A. Supervisor
- B. All members of the team
- C. Worker
- D. Quality assurance officer
Correct Answer: D. Quality assurance officer
17. Resistivity of a conductor is mostly affected by:
- A. Composition
- B. Pressure
- C. Temperature
- D. Current
Correct Answer: C. Temperature
18. What should you do when a problem arises while you are repairing electronic equipment that you
cannot solve by yourself?
- A. Quit repairing
- B. Throw it away
- C. Ask for assistance
- D. Murmuring & crying
Correct Answer: C. Ask for assistance
19. What is the power factor in capacitive circuits?
- A. Zero
- B. Unity
- C. Lagging
- D. Leading
Correct Answer: D. Leading
20. Dielectric materials are:
- A. Insulating materials
- B. Semiconducting materials
- C. Magnetic materials
- D. Ferroelectric materials
Correct Answer: A. Insulating materials
21. Transformer cores are laminated in order to:
- A. Simplify its construction
- B. Minimize eddy current loss
- C. Reduce loss
- D. Reduce hysteresis loss
Correct Answer: B. Minimize eddy current loss
22. Star-delta starter of an induction motor:
- A. Inserts resistance in the rotor circuit
- B. Inserts resistance in the stator circuit
- C. Applies reduced voltage to the rotor
- D. Applies reduced voltage to the stator
Correct Answer: D. Applies reduced voltage to the stator
23. The minimum change in input value that can be detected by measuring is called:
- A. Threshold
- B. Resolution
- C. Sensitivity
- D. Error
Correct Answer: B. Resolution
24. Multiplying resistor is required in:
- A. Ammeter
- B. Power
- C. Ohmmeter
- D. Voltmeter
Correct Answer: D. Voltmeter
25. A transformer having 1000 primary turns is connected to a 250V AC supply for a secondary voltage
of 400V. The number of secondary turns should be:
- A. 1600
- B. 250
- C. 400
- D. 125
Correct Answer: A. 1600
---
*(Continued for the remaining questions...)*
Let me know if you'd like the rest of the questions answered in the same format!
Here are the remaining questions with choices and correct answers marked:
---
26. Basic meter movement has an internal resistance of 50Ω and full-scale deflection current of 150mA.
What is the value of the shunt resistor required to measure?
- A. 200Ω
- B. 35Ω
- C. 15Ω
- D. 50Ω
Correct Answer: B. 35Ω *(Assuming range extension; exact calculation depends on desired range.)*
27. The difference between the synchronous speed and the actual speed of an induction motor is known
as:
- A. Regulation
- B. Backlash
- C. Slip
- D. Lag
Correct Answer: C. Slip
28. The aim of preventive maintenance is to:
- A. Increase the reliability of a tool or equipment.
- B. Increase the failure rate of a tool or equipment.
- C. Reduce the lifespan of a tool or equipment.
- D. Improve the standard quality of a tool or equipment.
Correct Answer: A. Increase the reliability of a tool or equipment.
29. An electronic component used as a switching device:
- A. Capacitor
- B. Zener diode
- C. Resistor
- D. Transistor
Correct Answer: D. Transistor
30. Analog display in instruments has the following advantage:
- A. The display can be set at any value between 0% and 100%.
- B. Read-off errors due to parallax scale.
- C. No conversion, reading more accurate.
- D. Measured value output directly.
Correct Answer: D. Measured value output directly.
31. Determination of electrical resistance from voltage measurement is a __ measuring method.
- A. Direct
- B. Comparison
- C. Indirect
- D. Record
Correct Answer: C. Indirect
32. Errors that remain constant through all repetitions of measurement are said to be:
- A. Random error
- B. Cross error
- C. Systematic error
- D. Deviation error
Correct Answer: C. Systematic error
33. A process control system is stable:
- A. If the controlled variable oscillates above and below.
- B. If it can return the controlled variable to steady state.
- C. If oscillation and steady-state value present in the output stage.
- D. If both oscillation and steady-state value present in the input stage.
Correct Answer: B. If it can return the controlled variable to steady state.
34. The word "calibrate" in mechatronics indicates:
- A. Supply giving feedback.
- B. Supply giving set point.
- C. Supply giving output value.
- D. Supply giving measured value.
Correct Answer: B. Supply giving set point.
35. The best application of capacitive transducer elements in a liquid factory is:
- A. To identify filled, underfilled, or overfilled containers.
- B. To identify the number of containers.
- C. To identify the size of containers.
- D. To identify the presence of containers.
Correct Answer: A. To identify filled, underfilled, or overfilled containers.
36. Pictorial representation of the cause-and-effect relationship between input and output of a physical
system:
- A. Block diagram
- B. Circuit diagram
- C. Valve
- D. Filter
Correct Answer: A. Block diagram
37. Supplies air to the pressure vessel through a pipeline, with resistance to flow provided by a
constriction:
- A. Hydraulic power system
- B. Electromechanical system
- C. Pneumatic system
- D. Transfer function
Correct Answer: C. Pneumatic system
38. A group of components that complete tasks or achieve desired results while working together is
called:
- A. Output system
- B. Sequence system
- C. Control system
- D. Succession system
Correct Answer: C. Control system
39. Which one is a displacement measurement sensor?
- A. Resistive sensor
- B. Light sensor
- C. Temperature sensor
- D. Light-emitting diode
Correct Answer: A. Resistive sensor
40. What is the input of the data acquisition system (DAS) to which a transducer is connected?
*(Incomplete question; likely answer: Signal conditioning unit)*
---
### Key Repeated Questions (Consolidated Answers):
- Q61/Q10: On-off control → B. Two position control.
- Q62/Q15: 3 identical parallel resistors → C. 1/3 times each resistor.
- Q69/Q21: Transformer core lamination → B. Minimize eddy current loss.
- Q70/Q22: Star-delta starter → D. Applies reduced voltage to stator.
- Q76/Q25: Transformer turns calculation → A. 1600 turns.
---
### Final Notes:
- Q50 (Impedance calculation):
- Given: Frequency = 60kHz, Inductance = 10mH.
- Formula: \( Z = 2\pi fL = 2\pi \times 60,000 \times 0.01 \approx 3768Ω \).
- Closest option: A. 37680 *(Likely typo; should be 3768Ω)*.
- Q100 (Shifting set point):
- Correct term: D. Regulation (maintaining set point despite disturbances).
Let me know if you need further clarification or additional questions!
Here are the remaining questions with choices and correct answers marked:
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41. The main advantages of closed-loop control system are:
- A) Reduced sensitivity to disturbance
- B) Complex and expensive to construct
- C) The loss of gain
- D) Quite easy to become unstable
Correct Answer: A) Reduced sensitivity to disturbance
42. Which option best describes the action of an opto-coupler?
- A) It breaks the contact when there is excess current
- B) It breaks the contact when there is excess voltage
- C) It transmits the input signal using fiber optics
- D) It isolates the PLC from the input voltage
Correct Answer: D) It isolates the PLC from the input voltage
43. __ is the pressure measured with respect to vacuum.
- A) Gauge pressure
- B) Atmospheric pressure
- C) Differential pressure
- D) Absolute pressure
Correct Answer: D) Absolute pressure
44. A type of transformer used for instrument purpose is:
- A) Voltage transformer
- B) Power transformer
- C) Current transformer
- D) Distribution transformer
Correct Answer: C) Current transformer
45. Seebeck effect:
- A) Voltage produced by thermocouple is proportional to temperature difference
- B) Voltage produced by thermocouple is constant
- C) Current produced by thermocouple is proportional to temperature
- D) Resistance changes with temperature
Correct Answer: A) Voltage produced by thermocouple is proportional to temperature difference
46. Accuracy is defined as:
- A) The measure of difference between indicated value and true value
- B) The ability to repeat measurements
- C) The smallest detectable change
- D) The range of measurements
Correct Answer: A) The measure of difference between indicated value and true value
47. What is the impedance of a 60kHz sine wave with 10mH inductance?
- A) 3768Ω
- B) 3500Ω
- C) 3668Ω
- D) 3778Ω
Correct Answer: A) 3768Ω (Calculation: 2πfL = 2×3.14×60000×0.01 ≈ 3768Ω)
48. What do we call transducers that do not require any secondary power to produce output?
- A) Active electrical component
- B) Active transducer
- C) Passive transducer
- D) Passive electrical component
Correct Answer: B) Active transducer
49. What is the purpose of zero error adjustment in measuring instruments?
- A) For identification of better failure
- B) For identification of multimeter
- C) To detect resolution of a meter
- D) To ensure accurate baseline measurement
Correct Answer: D) To ensure accurate baseline measurement
50. Which one affects conductor resistivity?
- A) Current
- B) Pyrometer
- C) Composition
- D) Pressure
Correct Answer: C) Composition
51. What do we call it when a measuring instrument provides the same measurement repeatedly?
- A) Processor
- B) Sensitivity
- C) Resolution
- D) Accuracy
Correct Answer: D) Accuracy
52. The core of a transformer is laminated in order to:
- A) Simplify its construction
- B) Reduce copper loss
- C) Minimize eddy current loss
- D) Reduce hysteresis loss
Correct Answer: C) Minimize eddy current loss
53. Instruments are divided into classes according to:
- A) The gross error of the measuring deviation
- B) Maximum relative error (e.g., 1.5%)
- C) Operation of electrical measuring instruments
- D) Fine measurement instruments
Correct Answer: B) Maximum relative error (e.g., 1.5%)
54. A starter for induction motor is required to:
- A) Reduce starting current
- B) Increase starting voltage
- C) Reduce rotary voltage
- D) Increase starting speed
Correct Answer: A) Reduce starting current
55. An output of PLC is:
- A) Sensor
- B) Sensitivity
- C) Actuator
- D) Mystery
Correct Answer: C) Actuator
56. Which is correct for input/output of PLC?
- A) Contactor and Motor
- B) Switch and Motor
- C) Switch and Sensor
- D) Lamp and Motor
Correct Answer: A) Contactor and Motor
57. A type of final control element that receives commands from controller:
- A) Pressure gauge and flow meter
- B) Temperature, pressure and level
- C) Valves and pumps
- D) Person switch and PLC
Correct Answer: C) Valves and pumps
58. The starting winding of a single phase motor is placed in the:
- A) Rotor
- B) Stator
- C) Armature
- D) Field
Correct Answer: B) Stator
59. The frequency of DC supply is:
- A) Zero
- B) 16Hz
- C) 50Hz
- D) 100Hz
Correct Answer: A) Zero
60. Brushes of DC machines are usually made of:
- A) Hard copper
- B) Soft copper
- C) Carbon
- D) All of above
Correct Answer: C) Carbon
61. One of the following devices can be used to isolate the control circuit from the load:
- A) Toggle switch
- B) Relay
- C) Circuit breaker
- D) Rotary switch
Correct Answer: B) Relay
62. When shifting of set point and adjusting its new value due to disturbance increase, this is called:
- A) Offset
- B) Stabilization
- C) Set shift
- D) Regulation
Correct Answer: D) Regulation
---
### Summary of Key Concepts:
1. Transformers: Laminated cores minimize eddy currents (Q21, Q55); turns ratio determines voltage
(Q25, Q76).
2. Sensors: Active transducers self-generate signals (Q48); strain gauges are passive (Q13).
3. Control Systems: Closed-loop reduces disturbances (Q41); regulation maintains set points (Q100).
4. Motors: Starters reduce inrush current (Q54); slip defines speed difference (Q27).
5. Measurements: Accuracy vs. resolution (Q23, Q51); systematic errors are consistent (Q32).
For symbols (Q101-102), please provide the options or diagrams for accurate identification. Let me know
if you need further explanations!
Here are the remaining questions with choices and correct answers marked:
---
63. The demand factor for an electrical system is the ratio of:
- A) Maximum demand to connected load
- B) Maximum demand to average load
- C) Average power to maximum power
- D) Relative power to total power
Correct Answer: A) Maximum demand to connected load
64. In a delta-connected three-phase generator, if one phase is opened:
- A) It stops generating
- B) It generates under the rated output
- C) It generates the rated output
- D) It is burned
Correct Answer: B) It generates under the rated output
65. A device that receives energy from one system and retransmits it to another system in another form
is called:
- A) Relay
- B) Ultrasonic sensor
- C) Limit switch
- D) Transducer
Correct Answer: D) Transducer
66. The basis of operation of a transformer is the effect of:
- A) Self-inductance
- B) Mutual-inductance
- C) Coupled-inductance
- D) Decoupled-inductance
Correct Answer: B) Mutual-inductance
67. In the following circuit, reactive element is obtained in:
- A) Filament lamp
- B) Cooking stove
- C) Lamp ballast
- D) None
Correct Answer: C) Lamp ballast
68. Written communication methods may include:
- A) Discussion
- B) Negotiation
- C) Speeches
- D) Instructions
Correct Answer: D) Instructions
69. A transformer has 1600 turns in the secondary. When a voltage of 16V is applied to the primary, an
EMF of 80V is induced in the secondary. The number of turns in the primary is:
- A) 320
- B) 3200
- C) 800
- D) 8000
Correct Answer: A) 320 (Calculation: Turns ratio = Vp/Vs = Np/Ns → 16/80 = Np/1600 → Np = 320)
70. Symbols of SCS:
*(Question incomplete - SCS typically stands for Silicon Controlled Switch, a four-layer semiconductor
device)*
71. Symbols of Schottky transistor:
*(Question incomplete - Schottky transistor combines a transistor and Schottky diode to prevent
saturation)*
---
### Key Technical Concepts Recap:
1. Electrical Systems:
- Demand factor compares peak usage to total capacity (Q63)
- Delta-connected generators lose partial capacity when a phase opens (Q64)
2. Transformers:
- Operate on mutual inductance principle (Q66)
- Turns ratio determines voltage transformation (Q69)
3. Components:
- Transducers convert energy forms (Q65)
- Lamp ballasts provide reactive impedance (Q67)
4. Communication:
- Written methods include instructions (Q68)
5. Special Devices:
- SCS (Silicon Controlled Switch) and Schottky transistors have unique symbols (Q70-71)
---
### Final Notes:
- For symbol questions (Q70-71), please provide the visual options for precise identification.
- Transformer calculations (Q25, Q69, Q76) consistently use the turns ratio formula: Vp/Vs = Np/Ns
- Power systems concepts (Q1, Q63) emphasize practical metrics like demand factor and frequency
ranges
Let me know if you need further clarification on any topic or additional questions!
Here are the remaining questions with choices and correct answers marked:
---
72. The minimum change in input value that can be detected by a measuring instrument is called:
- A) Threshold
- B) Resolution
- C) Sensitivity
- D) Error
Correct Answer: B) Resolution
73. Multiplying resistor is required in:
- A) Ammeter
- B) Power meter
- C) Ohmmeter
- D) Voltmeter
Correct Answer: D) Voltmeter
74. One of the following devices can be used to isolate the control circuit from the load:
- A) Toggle switch
- B) Relay
- C) Circuit breaker
- D) Rotary switch
Correct Answer: B) Relay
75. The aim of preventive maintenance is to:
- A) Increase the reliability of a tool or equipment
- B) Increase the failure rate of tool or equipment
- C) Reduce the life span of a tool or equipment
- D) Improve the standard quality of a tool or equipment
Correct Answer: A) Increase the reliability of a tool or equipment
76. A transformer having 1000 primary turns is connected to a 250V AC supply for a secondary voltage
of 400V. The number of secondary turns should be:
- A) 1600
- B) 250
- C) 400
- D) 125
Correct Answer: A) 1600 (Calculation: Ns = (Vs/Vp)×Np = (400/250)×1000 = 1600)
77. An electronic component which is used as switching device:
- A) Capacitor
- B) Zener diode
- C) Resistor
- D) Transistor
Correct Answer: D) Transistor
78. Basic meter movement has an internal resistance of 50Ω and full scale deflection current of 150mA.
What will be the value of the shunt resistor required to measure?
- A) 200Ω
- B) 35Ω
- C) 15Ω
- D) 50Ω
Correct Answer: B) 35Ω (Calculation depends on desired range extension)
79. The difference between the synchronous speed and the actual speed of an induction motor is known
as:
- A) Regulation
- B) Backlash
- C) Slip
- D) Lag
Correct Answer: C) Slip
80. Transformer has 1600 turns in the secondary. When a voltage of 16V is applied to the primary, an
EMF of 80V is induced in the secondary. The number of turns in the primary is:
- A) 320
- B) 3200
- C) 800
- D) 8000
Correct Answer: A) 320 (Calculation: Np = (Vp/Vs)×Ns = (16/80)×1600 = 320)
81. The basis of operation of transformer is the effect of:
- A) Self-inductance
- B) Mutual-inductance
- C) Coupled-inductance
- D) Decoupled-inductance
Correct Answer: B) Mutual-inductance
82. Of the following circuit, reactive element is obtained in:
- A) Filament lamp
- B) Cooking stove
- C) Lamp ballast
- D) None
Correct Answer: C) Lamp ballast
83. In delta connected three-phase generator, if one phase is opened:
- A) It stops generating
- B) It generates under the rated output
- C) It generates the rated output
- D) It is burned
Correct Answer: B) It generates under the rated output
84. Errors that remain constant through all repetition of measurement is said to be:
- A) Random error
- B) Cross error
- C) Systematic error
- D) Deviation error
Correct Answer: C) Systematic error
85. In a device that receives energy from one system in one form & retransmits it to another system:
- A) Relay
- B) Ultrasonic sensor
- C) Limit switch
- D) Transducer
Correct Answer: D) Transducer
100. When shifting of set point and adjusting its new value by the when the value of disturbance is
increased, this is said to be:
- A) Offset
- B) Stabilization
- C) Set shift
- D) Regulation
Correct Answer: D) Regulation
---
### Summary of Key Technical Concepts:
1. Measurement Systems:
- Resolution is the smallest detectable change (Q72)
- Voltmeters use multiplying resistors (Q73)
- Systematic errors are consistent (Q84)
2. Control Systems:
- Relays provide isolation (Q74)
- Regulation maintains set points (Q100)
3. Transformers:
- Operate on mutual inductance (Q81)
- Turns ratio determines voltage (Q76, Q80)
4. Motors:
- Slip is speed difference (Q79)
5. Maintenance:
- Preventive maintenance increases reliability (Q75)
6. Power Systems:
- Delta generators operate at reduced capacity with open phase (Q83)
7. Components:
- Transducers convert energy forms (Q85)
- Transistors are switching devices (Q77)
---
### Final Notes:
- For symbol questions (Q101-102), please provide the visual options for precise identification.
- Transformer calculations consistently use the turns ratio formula (Vp/Vs = Np/Ns)
- Measurement concepts emphasize resolution vs sensitivity (Q23, Q72)
Let me know if you need any clarification or have additional questions!
Here are the remaining questions with their correct answers marked:
86. The starting winding of a single-phase motor is placed in the:
- A) Rotor
- B) Stator
- C) Armature
- D) Field
✓ Correct Answer: B) Stator
87. The frequency of DC supply is:
- A) Zero
- B) 16Hz
- C) 50Hz
- D) 100Hz
✓ Correct Answer: A) Zero
88. Brushes of DC machines are usually made of:
- A) Hard copper
- B) Soft copper
- C) Carbon
- D) All of above
✓ Correct Answer: C) Carbon
89. One of the following devices can be used to isolate the control circuit from the load:
- A) Toggle switch
- B) Relay
- C) Circuit breaker
- D) Rotary switch
✓ Correct Answer: B) Relay
90. When shifting of set point and adjusting its new value due to disturbance increase, this is called:
- A) Offset
- B) Stabilization
- C) Set shift
- D) Regulation
✓ Correct Answer: D) Regulation
91. Symbols of SCS (Silicon Controlled Switch):
*(Question incomplete - typically represented as a four-layer semiconductor device symbol)*
92. Symbols of Schottky transistor:
*(Question incomplete - combines standard transistor symbol with Schottky diode)*
---
### Key Technical Concepts Summary:
1. Motor Fundamentals:
- Single-phase motors have starting windings in the stator (Q86)
- DC has zero frequency (Q87)
- DC machine brushes use carbon (Q88)
2. Control Systems:
- Relays provide electrical isolation (Q89)
- Regulation maintains set points (Q90)
3. Special Devices:
- SCS is a four-layer thyristor variant (Q91)
- Schottky transistors prevent saturation (Q92)
---
### Final Notes:
- For symbol identification (Q91-92), the complete symbol diagrams would be needed for precise
answers
- Motor and generator questions (Q86-88) cover fundamental construction details
- Control system questions emphasize practical components and concepts
This completes all questions from the document. Let me know if you need any clarification or have
additional questions!
