Industrial Sensors and Transducers — MCQs – EE

1. What is the main purpose of a sensor in industrial systems?
(A) To detect physical quantities and convert them into measurable signals
(B) To amplify electrical power
(C) To generate control pulses
(D) To store data

2. What is a transducer?
(A) A device that converts one form of energy into another
(B) A power amplifier
(C) A logic circuit
(D) A display module

3. Which of the following is a temperature sensor?
(A) Thermocouple
(B) LDR
(C) Hall Effect sensor
(D) Ultrasonic sensor

4. A thermistor is a type of:
(A) Temperature-dependent resistor
(B) Voltage regulator
(C) Pressure sensor
(D) Current limiter

5. Which sensor measures pressure?
(A) Piezoelectric sensor
(B) LDR
(C) Thermistor
(D) Potentiometer

6. An LVDT (Linear Variable Differential Transformer) measures:
(A) Linear displacement
(B) Temperature
(C) Magnetic field
(D) Humidity

7. A strain gauge is used to measure:
(A) Force or deformation
(B) Temperature
(C) Light intensity
(D) Magnetic field

8. Which of the following sensors detects light intensity?
(A) LDR (Light Dependent Resistor)
(B) Thermocouple
(C) Piezoelectric crystal
(D) Potentiometer

9. The Hall Effect sensor is used for:
(A) Magnetic field measurement
(B) Light intensity measurement
(C) Sound detection
(D) Temperature control

10. An RTD (Resistance Temperature Detector) operates based on:
(A) Change in resistance with temperature
(B) Change in capacitance
(C) Change in inductance
(D) Change in magnetic flux

11. A proximity sensor is used to:
(A) Detect the presence of an object without contact
(B) Measure temperature
(C) Measure frequency
(D) Detect pressure

12. Which of the following sensors can detect motion?
(A) PIR (Passive Infrared) sensor
(B) LDR
(C) Thermistor
(D) RTD

13. A capacitive sensor detects:
(A) Changes in dielectric constant
(B) Light intensity
(C) Temperature variation
(D) Frequency shift

14. Which type of transducer converts mechanical motion into electrical signal?
(A) Electromechanical transducer
(B) Electrostatic transducer
(C) Piezoelectric transducer
(D) Thermal transducer

15. Which sensor is used for level measurement in tanks?
(A) Ultrasonic sensor
(B) LDR
(C) RTD
(D) Strain gauge

16. A photoelectric sensor detects:
(A) Presence of an object using light beam interruption
(B) Sound levels
(C) Temperature
(D) Pressure

17. The tacho generator is used to measure:
(A) Speed of rotation
(B) Voltage
(C) Pressure
(D) Frequency

18. A flow sensor measures:
(A) Fluid flow rate
(B) Voltage change
(C) Light intensity
(D) Vibration

19. Which transducer converts sound waves into electrical signals?
(A) Microphone
(B) Speaker
(C) Piezo buzzer
(D) Transistor

20. An encoder is used to measure:
(A) Angular position or rotation
(B) Temperature
(C) Pressure
(D) Humidity

21. A load cell measures:
(A) Force or weight
(B) Speed
(C) Temperature
(D) Vibration

22. The thermocouple output is in the form of:
(A) Voltage
(B) Resistance
(C) Capacitance
(D) Inductance

23. Which of the following sensors works based on Doppler effect?
(A) Radar sensor
(B) LDR
(C) Thermistor
(D) Strain gauge

24. A gyroscope measures:
(A) Angular velocity
(B) Linear displacement
(C) Force
(D) Temperature

25. Which sensor is used for humidity measurement?
(A) Hygrometer
(B) Thermistor
(C) Strain gauge
(D) LVDT

26. Signal conditioning circuits in sensors are used to:
(A) Amplify, filter, and convert signals
(B) Store sensor data
(C) Provide power to transducers
(D) Generate PWM signals

27. The transduction element in a sensor is responsible for:
(A) Converting one form of energy to another
(B) Storing data
(C) Filtering signals
(D) Amplifying current

28. Which type of sensor is commonly used in industrial robotic arms for position feedback?
(A) Rotary encoder
(B) LDR
(C) RTD
(D) Piezoelectric sensor

29. In industrial automation, sensors are used primarily for:
(A) Monitoring and feedback control
(B) Increasing signal noise
(C) Power amplification
(D) Data encryption

30. Which of the following is a non-contact type sensor?
(A) Ultrasonic sensor
(B) Potentiometer
(C) Strain gauge
(D) Thermistor