Transducers and Signal Conditioning — MCQs – EE

1. What is a transducer?
(A) A device that converts one form of energy into another
(B) A device that stores energy
(C) A signal amplifier
(D) A voltage regulator

2. A sensor is a device that:
(A) Detects or measures a physical quantity and converts it into a signal
(B) Amplifies an input signal
(C) Controls current in a circuit
(D) Displays electrical data only

3. The primary element of a transducer is responsible for:
(A) Sensing the input physical quantity
(B) Amplifying the electrical signal
(C) Displaying the output
(D) Converting analog to digital signals

4. The secondary element of a transducer:
(A) Converts the sensed signal into a usable electrical signal
(B) Stores mechanical energy
(C) Displays measurement
(D) Filters unwanted signals

5. A passive transducer requires:
(A) An external power source
(B) No power source
(C) Battery backup
(D) Mechanical excitation

6. An active transducer:
(A) Generates its own electrical signal
(B) Requires external excitation
(C) Works only with AC power
(D) Has no sensing element

7. Which of the following is an active transducer?
(A) Thermocouple
(B) LVDT
(C) Strain gauge
(D) RTD

8. Which of the following is a passive transducer?
(A) LVDT
(B) Piezoelectric sensor
(C) Photovoltaic cell
(D) Thermocouple

9. The piezoelectric effect is used in which type of transducer?
(A) Dynamic pressure sensor
(B) Temperature sensor
(C) Flow meter
(D) Displacement sensor

10. A strain gauge measures:
(A) Mechanical strain or deformation
(B) Voltage
(C) Current
(D) Temperature

11. The resistance of a strain gauge changes when:
(A) It is stretched or compressed
(B) Temperature increases
(C) Pressure decreases
(D) Voltage drops

12. The LVDT (Linear Variable Differential Transformer) measures:
(A) Linear displacement
(B) Angular velocity
(C) Flow rate
(D) Pressure

13. The output of an LVDT is:
(A) An AC voltage proportional to displacement
(B) A DC voltage proportional to force
(C) A current proportional to pressure
(D) A frequency signal

14. A thermistor is a type of:
(A) Resistive transducer
(B) Inductive transducer
(C) Capacitive transducer
(D) Piezoelectric transducer

15. The photoelectric transducer converts:
(A) Light energy into electrical energy
(B) Electrical energy into light
(C) Heat into motion
(D) Voltage into frequency

16. A tachogenerator is used to measure:
(A) Rotational speed
(B) Pressure
(C) Temperature
(D) Displacement

17. A potentiometer used as a transducer converts:
(A) Displacement into voltage
(B) Voltage into current
(C) Temperature into resistance
(D) Pressure into torque

18. The Hall effect transducer is used to measure:
(A) Magnetic field strength
(B) Temperature
(C) Pressure
(D) Capacitance

19. The photovoltaic effect is utilized in:
(A) Solar cells
(B) LVDT
(C) Piezoelectric sensors
(D) Strain gauges

20. Signal conditioning refers to:
(A) Processing sensor signals for further use
(B) Storing data from sensors
(C) Generating reference signals
(D) Displaying output on screen

21. The main functions of signal conditioning include:
(A) Amplification, filtering, and conversion
(B) Storage and retrieval
(C) Voltage regulation only
(D) Power distribution

22. An instrumentation amplifier is used in signal conditioning to:
(A) Amplify small differential signals
(B) Generate signals
(C) Measure frequency
(D) Reduce gain

23. A filter circuit in signal conditioning is used to:
(A) Remove noise and unwanted frequencies
(B) Amplify weak signals
(C) Store data temporarily
(D) Generate square waves

24. Isolation amplifiers are used to:
(A) Prevent ground loops and protect circuits
(B) Increase gain
(C) Convert analog to digital signals
(D) Reduce power consumption

25. The bridge circuit is commonly used in:
(A) Resistive transducer measurements
(B) Inductive sensors only
(C) Light sensors
(D) Capacitor charging

26. The Wheatstone bridge is primarily used to measure:
(A) Small resistance changes
(B) Capacitance
(C) Voltage gain
(D) Inductance

27. Analog-to-Digital Converters (ADC) are used to:
(A) Convert analog signals into digital form
(B) Convert digital signals into analog
(C) Amplify small signals
(D) Filter noise

28. Digital-to-Analog Converters (DAC) are used to:
(A) Convert digital signals into analog
(B) Amplify digital signals
(C) Filter analog signals
(D) Display numeric data

29. The sampling rate in signal conditioning refers to:
(A) The number of times an analog signal is measured per second
(B) The output frequency
(C) The gain of the amplifier
(D) The delay in transmission

30. The Nyquist rate is defined as:
(A) Twice the highest frequency component of the signal
(B) Half the sampling frequency
(C) The lowest signal frequency
(D) The cutoff frequency of a filter

31. A low-pass filter allows:
(A) Low-frequency signals to pass and attenuates high-frequency signals
(B) High-frequency signals to pass
(C) Only DC signals
(D) Noise to pass

32. A high-pass filter allows:
(A) High-frequency signals to pass and attenuates low-frequency signals
(B) Low-frequency signals only
(C) Only DC
(D) Noise and distortion

33. Impedance matching in signal conditioning ensures:
(A) Maximum power transfer
(B) Voltage amplification
(C) Signal attenuation
(D) Frequency doubling

34. The signal-to-noise ratio (SNR) indicates:
(A) The quality of a signal compared to background noise
(B) The frequency of a signal
(C) The gain of the amplifier
(D) The total energy of a signal

35. The drift in a transducer output refers to:
(A) Gradual change in output under constant input
(B) Sudden noise spikes
(C) Calibration error
(D) Phase shift