1. What is the primary function of a sensor?
(A) To convert a physical quantity into an electrical signal
(B) To amplify voltage
(C) To store energy
(D) To generate heat
2. The process of converting one form of energy into another is called:
(A) Transduction
(B) Transformation
(C) Transmission
(D) Translation
3. Which of the following sensors is used to measure temperature?
(A) Thermocouple
(B) LVDT
(C) Strain gauge
(D) Photodiode
4. A transducer is a device that:
(A) Converts non-electrical energy into electrical energy or vice versa
(B) Stores electrical charge
(C) Controls current flow
(D) Filters noise
5. A thermistor changes its resistance with:
(A) Temperature
(B) Pressure
(C) Light intensity
(D) Sound
6. Which of the following is a primary transducer?
(A) Bourdon tube
(B) LVDT
(C) Strain gauge
(D) Thermocouple
7. A secondary transducer converts:
(A) Output of a primary transducer into an electrical signal
(B) Electrical signal into temperature
(C) Voltage into magnetic flux
(D) Pressure into displacement directly
8. The working principle of an LVDT (Linear Variable Differential Transformer) is based on:
(A) Electromagnetic induction
(B) Piezoelectric effect
(C) Photoelectric effect
(D) Thermoelectric effect
9. A strain gauge operates on the principle of:
(A) Change in resistance due to deformation
(B) Change in capacitance
(C) Magnetic field variation
(D) Photoelectric conversion
10. A piezoelectric transducer works on which principle?
(A) Generation of voltage due to mechanical stress
(B) Change in capacitance
(C) Induction of current due to heat
(D) Variation of magnetic flux
11. A photodiode converts:
(A) Light energy into electrical current
(B) Voltage into frequency
(C) Pressure into displacement
(D) Sound into heat
12. The Hall effect sensor is used to measure:
(A) Magnetic field strength
(B) Pressure
(C) Temperature
(D) Light intensity
13. A capacitive sensor measures displacement by:
(A) Change in capacitance due to distance variation
(B) Change in resistance
(C) Change in inductance
(D) Photoelectric conversion
14. The Seebeck effect is the basis of:
(A) Thermocouple operation
(B) Strain gauge
(C) Capacitive sensor
(D) Optical encoder
15. A phototransistor is sensitive to:
(A) Light
(B) Sound
(C) Pressure
(D) Temperature
16. A resistive transducer converts:
(A) Change in physical quantity into change in resistance
(B) Voltage to current
(C) Current to light
(D) Heat to force
17. The electromagnetic induction principle is used in:
(A) Inductive sensors
(B) Thermistors
(C) Piezoelectric sensors
(D) Optical sensors
18. Which transducer uses Coulomb’s law for its operation?
(A) Capacitive transducer
(B) Inductive transducer
(C) Piezoelectric transducer
(D) Photodiode
19. A piezoresistive sensor changes resistance due to:
(A) Applied mechanical stress
(B) Change in light intensity
(C) Temperature rise
(D) Magnetic field
20. The photoelectric effect is utilized in:
(A) Light sensors and optical encoders
(B) Pressure gauges
(C) Strain sensors
(D) Thermistors
21. A tachogenerator is used to measure:
(A) Speed
(B) Temperature
(C) Pressure
(D) Vibration
22. Which of the following is an active transducer?
(A) Thermocouple
(B) LVDT
(C) Strain gauge
(D) RTD
23. Passive transducers require:
(A) External power supply
(B) No external energy source
(C) Only thermal energy
(D) Only mechanical excitation
24. An RTD (Resistance Temperature Detector) is based on:
(A) Change in resistance of metal with temperature
(B) Voltage induction
(C) Photoelectric effect
(D) Capacitance variation
25. A potentiometer used as a transducer converts:
(A) Displacement into voltage
(B) Temperature into current
(C) Pressure into frequency
(D) Force into capacitance
26. Optical encoders are used to measure:
(A) Angular position or speed
(B) Temperature
(C) Magnetic field
(D) Pressure
27. The inductive proximity sensor detects objects based on:
(A) Change in magnetic field
(B) Temperature difference
(C) Capacitance variation
(D) Pressure difference
28. In a thermopile, multiple thermocouples are connected:
(A) In series to increase output voltage
(B) In parallel to reduce resistance
(C) Randomly to balance current
(D) Opposite directions to cancel noise
29. A flow sensor using a hot-wire principle works based on:
(A) Cooling effect of fluid flow on heated wire
(B) Piezoelectric stress
(C) Magnetic field strength
(D) Capacitance variation
30. The main advantage of smart transducers is:
(A) Integration of sensing, processing, and communication in one unit
(B) Need for manual calibration
(C) No signal conditioning
(D) Simple mechanical operation only