Red Seal Interprovincial Examination
Instrumentation and Control Technician
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
Download Pdf
1. Which type of sensor is commonly used to measure temperature
in a process control system?
a) Strain gauge
b) LVDT
c) Thermocouple
d) Photocell
c) Thermocouple
Thermocouples are widely used for temperature measurement
because they are durable, can measure a wide range of
temperatures, and provide a fast response.
2. What does a 4-20 mA signal represent in instrumentation
systems?
a) Voltage output from a transducer
b) Digital signal
c) Standard analog signal
d) Resistance measurement
c) Standard analog signal
4-20 mA is the standard current loop used for transmitting analog
signals over long distances with low signal loss.
,3. Which device converts a physical variable into an electrical signal?
a) Actuator
b) Transducer
c) Controller
d) Relay
b) Transducer
A transducer converts a physical property (like temperature,
pressure, or flow) into a measurable electrical signal.
4. In control systems, what is the purpose of a PID controller?
a) To convert analog signals to digital
b) To maintain a process variable at a desired setpoint
c) To amplify signals
d) To isolate electrical circuits
b) To maintain a process variable at a desired setpoint
PID controllers continuously calculate an error value and adjust
the output to minimize the difference between process variable
and setpoint.
5. What is the primary function of a pressure transmitter?
a) To control fluid flow
b) To measure pressure and transmit an electrical signal
c) To open and close valves
d) To amplify current
b) To measure pressure and transmit an electrical signal
Pressure transmitters sense process pressure and convert it into a
standard signal (e.g., 4-20 mA) for monitoring or control.
6. Which type of valve is best for modulating flow in a process
system?
, a) Ball valve
b) Gate valve
c) Globe valve
d) Check valve
c) Globe valve
Globe valves provide precise control of flow rates, making them
ideal for modulation.
7. What is the main purpose of a signal isolator?
a) To amplify signals
b) To provide electrical isolation and prevent ground loops
c) To convert analog signals to digital
d) To control motor speed
b) To provide electrical isolation and prevent ground loops
Signal isolators prevent interference and protect sensitive
equipment by electrically isolating input and output circuits.
8. Which of the following sensors is suitable for non-contact level
measurement?
a) Float switch
b) Capacitive sensor
c) Radar level transmitter
d) Differential pressure transmitter
c) Radar level transmitter
Radar level transmitters use microwave signals to measure liquid
or solid levels without touching the material.
9. What does HART communication protocol allow?
a) Only analog transmission
b) Digital communication over a 4-20 mA loop
, c) Wireless communication
d) Control of motors
b) Digital communication over a 4-20 mA loop
HART allows digital information to be transmitted simultaneously
with a standard 4-20 mA signal.
10. In a process control loop, what is the purpose of a valve
positioner?
a) To measure flow
b) To ensure the valve reaches the commanded position
accurately
c) To sense pressure
d) To convert analog to digital signals
b) To ensure the valve reaches the commanded position
accurately
Valve positioners adjust actuator input to achieve precise valve
positioning as commanded by the controller.
11. Which type of sensor is used to measure vibration in rotating
machinery?
a) Thermocouple
b) Piezoelectric accelerometer
c) Strain gauge
d) LVDT
b) Piezoelectric accelerometer
Piezoelectric accelerometers convert mechanical vibration into an
electrical signal proportional to acceleration.
12. What is the function of a differential pressure transmitter in
a flow measurement system?
Instrumentation and Control Technician
Questions And Correct Answers (Verified
Answers) Plus Rationales 2026 Q&A | Instant
Download Pdf
1. Which type of sensor is commonly used to measure temperature
in a process control system?
a) Strain gauge
b) LVDT
c) Thermocouple
d) Photocell
c) Thermocouple
Thermocouples are widely used for temperature measurement
because they are durable, can measure a wide range of
temperatures, and provide a fast response.
2. What does a 4-20 mA signal represent in instrumentation
systems?
a) Voltage output from a transducer
b) Digital signal
c) Standard analog signal
d) Resistance measurement
c) Standard analog signal
4-20 mA is the standard current loop used for transmitting analog
signals over long distances with low signal loss.
,3. Which device converts a physical variable into an electrical signal?
a) Actuator
b) Transducer
c) Controller
d) Relay
b) Transducer
A transducer converts a physical property (like temperature,
pressure, or flow) into a measurable electrical signal.
4. In control systems, what is the purpose of a PID controller?
a) To convert analog signals to digital
b) To maintain a process variable at a desired setpoint
c) To amplify signals
d) To isolate electrical circuits
b) To maintain a process variable at a desired setpoint
PID controllers continuously calculate an error value and adjust
the output to minimize the difference between process variable
and setpoint.
5. What is the primary function of a pressure transmitter?
a) To control fluid flow
b) To measure pressure and transmit an electrical signal
c) To open and close valves
d) To amplify current
b) To measure pressure and transmit an electrical signal
Pressure transmitters sense process pressure and convert it into a
standard signal (e.g., 4-20 mA) for monitoring or control.
6. Which type of valve is best for modulating flow in a process
system?
, a) Ball valve
b) Gate valve
c) Globe valve
d) Check valve
c) Globe valve
Globe valves provide precise control of flow rates, making them
ideal for modulation.
7. What is the main purpose of a signal isolator?
a) To amplify signals
b) To provide electrical isolation and prevent ground loops
c) To convert analog signals to digital
d) To control motor speed
b) To provide electrical isolation and prevent ground loops
Signal isolators prevent interference and protect sensitive
equipment by electrically isolating input and output circuits.
8. Which of the following sensors is suitable for non-contact level
measurement?
a) Float switch
b) Capacitive sensor
c) Radar level transmitter
d) Differential pressure transmitter
c) Radar level transmitter
Radar level transmitters use microwave signals to measure liquid
or solid levels without touching the material.
9. What does HART communication protocol allow?
a) Only analog transmission
b) Digital communication over a 4-20 mA loop
, c) Wireless communication
d) Control of motors
b) Digital communication over a 4-20 mA loop
HART allows digital information to be transmitted simultaneously
with a standard 4-20 mA signal.
10. In a process control loop, what is the purpose of a valve
positioner?
a) To measure flow
b) To ensure the valve reaches the commanded position
accurately
c) To sense pressure
d) To convert analog to digital signals
b) To ensure the valve reaches the commanded position
accurately
Valve positioners adjust actuator input to achieve precise valve
positioning as commanded by the controller.
11. Which type of sensor is used to measure vibration in rotating
machinery?
a) Thermocouple
b) Piezoelectric accelerometer
c) Strain gauge
d) LVDT
b) Piezoelectric accelerometer
Piezoelectric accelerometers convert mechanical vibration into an
electrical signal proportional to acceleration.
12. What is the function of a differential pressure transmitter in
a flow measurement system?
