TRANSDUCERS Quiz Electronics Instrument Engineering

TRANSDUCERS Quiz Electronics Instrument Engineering


1. Self generating type transducers are ___________ transducers.
a) Active
b) Passive
c) Secondary
d) Inverse
Ans : (a)

2. The transducers that converts the input signal into the output signal, which is a discrete function of time is known as ___________ transducer.
a) Active
b) Analog
c) Digital
d) Pulse
Ans : (c)

3. A transducer that converts measurand into the form of pulse is called
a) Active transducer
b) Analog transducer
c) Digital transducer
d) Pulse transducer
Ans : (d)

4. Which of the following is a digital transducer?
a) Strain gauge
b) Encoder
c) Thermistor
d) LVDT
Ans : (b)

5. Strain gauge, LVDT and thermocouple are examples of
a) Active transducers
b) Passive transducers
c) Analog transducers
d) Primary transducers
Ans : (c)

6. An inverse transducer is a device which converts
a) An electrical quantity into a non electrical quantity
b) Electrical quantity into mechanical quantity
c) Electrical energy into thermal energy
d) Electrical energy into light energy
Ans : (a)

7. A strain gauge is a passive transducer and is employed for converting
a) Mechanical displacement into a change of resistance
b) Pressure into a change of resistance
c) Force into a displacement
d) Pressure into displacement
Ans : (a)

8. Resolution of a transducer depends on
a) Material of wire
b) Length of wire
c) Diameter of wire
d) Excitation voltage
Ans : (c)

9. The gauge factor is given as
a) ∆R/R
∆I/I
b) ∆I/I
∆R/R
c) ∆R/R
∆D/D
d) ∆D/D
∆R/R
Ans : (a)

10. The gauge factor G and the poisons ratio µ are related as
a) G = 1+µ
b) G = µ
c) G = 1+2µ
d) G = 1+µ /2
Ans : (a)

11. The sensitivity factor of strain gauge is normally of the order of
a) 1 to 1.5
b) 1.5 to 2.0
c) 0.5 to 1.0
d) 5 to 10
Ans : (b)

12. In wire wound strain gauges, the change in resistance is due to
a) Change in diameter of the wire
b) Change in length of the wire
c) Change in both length and diameter
d) Change in resistivity
Ans : (c)

13. Bonded wire strain gauges are
a) Exclusively used for construction of transducers
b) Exclusively used for stress analysis
c) Used for both stress analysis and construction of transducer
d) Pressure measurement
Ans : (c)

14. Certain type of materials generates an electrostatic charge or voltage when mechanical force is applied across them. Such materials are called
a) Piezo-electric
b) Photo-electric
c) Thermo-electric
d) Photo-resistive
Ans : (a)

15. Quartz and Rochelle salt belongs to ___________ of piezo-electric materials
a) Natural group
b) Synthetic group
c) Natural or Synthetic group
d) Fiber group
Ans : (a)

16. Which of the following are piezo electric substances?
1. Barium titanate
2. Lead titanate
3. Lead Zirconate
4. Cadmium and sulphate
a) 1,2 and 4
b) 1,3and4
c) 1,2and 3
d) 2,3and 4
Ans : (c)

17. Piezo-electric transducers are
a) Passive transducers
b) Inverse transducers
c) Digital transducers
d) Pulse transducers
Ans : (b)

18. Piezo - electric transducers work when we apply _____________ to it.
a) Mechanical force
b) Vibrations
c) Illuminations
d) Heat
Ans : (d)
19. Piezo electric crystal can produce an emf
a) When external mechanical force is applied to i
b) When radiant energy stimulates the crystal
c) When external magnetic field is applied
d) When the junction of two such crystals are heated Ans : (a)

20. The draw backs of strain gauges are
S1: Low fatigue life
S2: They are expensive, brittle and sensitive to temperature
S3: Poor linearity
a) S1 and S2
b) S2 and S3
c) S1 and S3
d) S1 only
Ans : (b)

21. LVDT windings are wound on
a) Steel sheets
b) Aluminium
c) Ferrite
d) Copper
Ans : (c)

22. The size of air cored transducers in comparison to the iron core parts is
a) Smaller
b) Larger
c) Same
d) Unpredictable
Ans : (b)

23. The principle of operation of LVDT is based on the variation of
a) Self inductance
b) Mutual inductance
c) Reluctance
d) Permanence
Ans : (b)

24. LVDT is an/a ___________ transducer
a) Magneto-strict ion
b) Inductive
c) Resistive
d) Eddy current
Ans : (d)

25. Which of the following can be measured with the help of piezo electric crystal?
a) Force
b) Velocity
c) Sound
d) Pressure
Ans : (a)

26. S1: Transducer is a device which converts physical into electrical quantity
S2: Transducer is also called as sensor.
a) S1 is true & S2 is false
b) S2 is true & S1 is false
c) Both S1 & S2 are true
d) Both S1 & S2 are false
Ans (b)


27. In a LVDT, the two secondary voltages
a) Are independent of the core position
b) Vary unequally depending on the core position
c) Vary equally depending on the core position
d) Are always in phase quadrature
Ans : (b)

28. Capacitive transducers are normally employed for___________ measurements
a) Static
b) Dynamic
c) Transient
d) Both static and dynamic
Ans : (b)

29. Match the following
1. EEG A. Diagnostic tool for heart alignment
2. ECG B. Diagnostic tool for brain alignment
3. Sphygmo-manometer C. Instrument used for measuring blood pressure
4. Stethoscope D. instrument used to hear pulse/heart beat
a) 1- B, 2 - A, 3 - C, 4 - D
b) 1 - B, 2 - A, 3 - D, 4 - C
c) 1- C, 2 - A, 3 - B, 4 - D
d) 1 - A, 2 - B, 3 - C, 4 - D
Ans : (a)

30. Pick the correct statement regarding functions of a transducer
S1: Sense the magnitude, change in & / or frequency of same measurand
S2: To provide electrical output that furnishes accurate, quantitative data about the measurand
a) S1 is true & S2 is false
b) S2 is true & S1 is false
c) Both S1 & S2 are true
d) Both S1 & S2 are false
Ans : (c)