Mechatronics Technician Certification
Examination Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
Question 1
What is the primary function of a programmable logic controller (PLC) in a
mechatronic system?
A. To perform high-speed mathematical computations for robotic kinematics
B. To replace hydraulic actuators with electronic motor drives
C. To provide real-time control of industrial processes through digital logic and I/O
handling
D. To serve as a wireless communication bridge between sensors and cloud
databases
Answer: C. To provide real-time control of industrial processes through digital logic
and I/O handling
Rationale: PLCs are designed for rugged industrial environments and execute
ladder logic or structured text to monitor inputs and control outputs in real time.
While they can perform math and communicate, their core mission is process
control via deterministic scanning, not cloud bridging or actuator replacement.
Question 2
Which sensor type is most appropriate for measuring angular position of a motor
shaft with high resolution and no cumulative error?
,A. Potentiometer
B. Optical incremental encoder
C. Absolute rotary encoder
D. Hall effect switch
Answer: C. Absolute rotary encoder
Rationale: Absolute encoders provide a unique digital code for each shaft position,
so power loss does not cause loss of reference. Incremental encoders count pulses
and can accumulate error; potentiometers are analog and wear-prone; Hall
switches only detect presence.
Question 3
In a pneumatic system, what does a 5/2 directional control valve indicate?
A. Five ports and two positions
B. Five actuators and two cylinders
C. Five flow rates and two pressure settings
D. Five solenoids and two springs
Answer: A. Five ports and two positions
Rationale: The notation 5/2 means the valve has five connection ports (supply,
two cylinder ports, two exhausts) and two switching positions, commonly used to
control double-acting cylinders.
Question 4
A stepper motor with a step angle of 1.8° is driven at 2000 pulses per second.
What is the shaft speed in revolutions per minute (RPM)?
A. 600 RPM
B. 300 RPM
C. 150 RPM
D. 1200 RPM
,Answer: A. 600 RPM
Rationale: Steps per revolution = 360/1.8 = 200. Pulses per second = 2000, so rev/s
= 2000/200 = 10. RPM = 10 * 60 = 600.
Question 5
Which of the following is a characteristic of a closed-loop control system
compared to an open-loop system?
A. Lower cost and simpler tuning
B. No need for feedback sensors
C. Greater immunity to disturbances and parameter variations
D. Faster response without stability concerns
Answer: C. Greater immunity to disturbances and parameter variations
Rationale: Closed-loop systems use feedback to compare actual output to
reference, allowing correction for disturbances and changes in plant dynamics.
Open-loop systems lack this correction. Closed-loop systems are generally more
expensive and can become unstable if poorly tuned.
Question 6
What is the purpose of a diode placed in parallel with a relay coil in a DC circuit?
A. To increase the coil’s inductance
B. To clamp the inductive kickback voltage and protect transistors
C. To rectify AC current into DC for the coil
D. To reduce the coil’s holding current
Answer: B. To clamp the inductive kickback voltage and protect transistors
Rationale: When a relay coil de-energizes, its magnetic field collapses, generating
a high-voltage spike (flyback). A flyback diode (freewheeling diode) provides a
path for this current, preventing damage to switching transistors or
microcontrollers.
, Question 7
In ladder logic, which instruction is used to create a seal-in circuit (latching)
without using a set/reset coil?
A. An examine-on (XIC) in parallel with the start contact
B. A timer-on-delay (TON) in series with the output
C. A one-shot (OSR) instruction before the output
D. A counter (CTU) resetting the output
Answer: A. An examine-on (XIC) in parallel with the start contact
Rationale: A seal-in circuit uses the output’s normally open contact (XIC) in
parallel with the momentary start pushbutton. Once the output energizes, it holds
itself on even after the start button is released, until a normally closed stop contact
breaks the circuit.
Question 8
Which material is most commonly used for the core of an inductive proximity
sensor’s oscillator coil?
A. Aluminum
B. Copper
C. Ferrite
D. Air
Answer: C. Ferrite
Rationale: Ferrite has high magnetic permeability and low electrical conductivity,
which concentrates the magnetic field and reduces eddy current losses, making it
ideal for high-frequency oscillator coils in inductive sensors.
Question 9
A hydraulic pump delivers 20 GPM at 1500 PSI. What is the hydraulic horsepower
output? (Use HHP = (GPM × PSI) / 1714)
A. 17.5 HP
B. 10.5 HP
Examination Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
Question 1
What is the primary function of a programmable logic controller (PLC) in a
mechatronic system?
A. To perform high-speed mathematical computations for robotic kinematics
B. To replace hydraulic actuators with electronic motor drives
C. To provide real-time control of industrial processes through digital logic and I/O
handling
D. To serve as a wireless communication bridge between sensors and cloud
databases
Answer: C. To provide real-time control of industrial processes through digital logic
and I/O handling
Rationale: PLCs are designed for rugged industrial environments and execute
ladder logic or structured text to monitor inputs and control outputs in real time.
While they can perform math and communicate, their core mission is process
control via deterministic scanning, not cloud bridging or actuator replacement.
Question 2
Which sensor type is most appropriate for measuring angular position of a motor
shaft with high resolution and no cumulative error?
,A. Potentiometer
B. Optical incremental encoder
C. Absolute rotary encoder
D. Hall effect switch
Answer: C. Absolute rotary encoder
Rationale: Absolute encoders provide a unique digital code for each shaft position,
so power loss does not cause loss of reference. Incremental encoders count pulses
and can accumulate error; potentiometers are analog and wear-prone; Hall
switches only detect presence.
Question 3
In a pneumatic system, what does a 5/2 directional control valve indicate?
A. Five ports and two positions
B. Five actuators and two cylinders
C. Five flow rates and two pressure settings
D. Five solenoids and two springs
Answer: A. Five ports and two positions
Rationale: The notation 5/2 means the valve has five connection ports (supply,
two cylinder ports, two exhausts) and two switching positions, commonly used to
control double-acting cylinders.
Question 4
A stepper motor with a step angle of 1.8° is driven at 2000 pulses per second.
What is the shaft speed in revolutions per minute (RPM)?
A. 600 RPM
B. 300 RPM
C. 150 RPM
D. 1200 RPM
,Answer: A. 600 RPM
Rationale: Steps per revolution = 360/1.8 = 200. Pulses per second = 2000, so rev/s
= 2000/200 = 10. RPM = 10 * 60 = 600.
Question 5
Which of the following is a characteristic of a closed-loop control system
compared to an open-loop system?
A. Lower cost and simpler tuning
B. No need for feedback sensors
C. Greater immunity to disturbances and parameter variations
D. Faster response without stability concerns
Answer: C. Greater immunity to disturbances and parameter variations
Rationale: Closed-loop systems use feedback to compare actual output to
reference, allowing correction for disturbances and changes in plant dynamics.
Open-loop systems lack this correction. Closed-loop systems are generally more
expensive and can become unstable if poorly tuned.
Question 6
What is the purpose of a diode placed in parallel with a relay coil in a DC circuit?
A. To increase the coil’s inductance
B. To clamp the inductive kickback voltage and protect transistors
C. To rectify AC current into DC for the coil
D. To reduce the coil’s holding current
Answer: B. To clamp the inductive kickback voltage and protect transistors
Rationale: When a relay coil de-energizes, its magnetic field collapses, generating
a high-voltage spike (flyback). A flyback diode (freewheeling diode) provides a
path for this current, preventing damage to switching transistors or
microcontrollers.
, Question 7
In ladder logic, which instruction is used to create a seal-in circuit (latching)
without using a set/reset coil?
A. An examine-on (XIC) in parallel with the start contact
B. A timer-on-delay (TON) in series with the output
C. A one-shot (OSR) instruction before the output
D. A counter (CTU) resetting the output
Answer: A. An examine-on (XIC) in parallel with the start contact
Rationale: A seal-in circuit uses the output’s normally open contact (XIC) in
parallel with the momentary start pushbutton. Once the output energizes, it holds
itself on even after the start button is released, until a normally closed stop contact
breaks the circuit.
Question 8
Which material is most commonly used for the core of an inductive proximity
sensor’s oscillator coil?
A. Aluminum
B. Copper
C. Ferrite
D. Air
Answer: C. Ferrite
Rationale: Ferrite has high magnetic permeability and low electrical conductivity,
which concentrates the magnetic field and reduces eddy current losses, making it
ideal for high-frequency oscillator coils in inductive sensors.
Question 9
A hydraulic pump delivers 20 GPM at 1500 PSI. What is the hydraulic horsepower
output? (Use HHP = (GPM × PSI) / 1714)
A. 17.5 HP
B. 10.5 HP
