TRANSDUCERS QUIZ ELECTRONICS & INSTRUMENTATION

1. Self generating type transducers are ___________ transducers.a) Activeb) Passivec) Secondaryd) InverseAns : (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) Activeb) Analogc) Digitald) PulseAns : (c)

3. A transducer that converts measurand into the form of pulse is calleda) Active transducerb) Analog transducerc) Digital transducerd) Pulse transducerAns : (d)

4. Which of the following is a digital transducer?a) Strain gaugeb) Encoderc) Thermistord) LVDTAns : (b)

5. Strain gauge, LVDT and thermocouple are examples ofa) Active transducersb) Passive transducersc) Analog transducersd) Primary transducersAns : (c)

6. An inverse transducer is a device which convertsa) An electrical quantity into a non electrical quantityb) Electrical quantity into mechanical quantityc) Electrical energy into thermal energyd) Electrical energy into light energyAns : (a)

7. A strain gauge is a passive transducer and is employed for convertinga) Mechanical displacement into a change of resistanceb) Pressure into a change of resistancec) Force into a displacementd) Pressure into displacementAns : (a)

8. Resolution of a transducer depends ona) Material of wireb) Length of wirec) Diameter of wired) Excitation voltageAns : (c)

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

10. In wire wound strain gauges, the change in resistance is due toa) Change in diameter of the wireb) Change in length of the wirec) Change in both length and diameterd) Change in resistivityAns : (c)

11. Bonded wire strain gauges are

a) Exclusively used for construction of transducersb) Exclusively used for stress analysisc) Used for both stress analysis and construction of transducerd) Pressure measurementAns : (c)

12. Certain type of materials generates an electrostatic charge or voltage when mechanical force is applied across them. Such materials are calleda) Piezo-electricb) Photo-electricc) Thermo-electricd) Photo-resistiveAns : (a)

13. Quartz and Rochelle salt belongs to ___________ of piezo-electric materialsa) Natural groupb) Synthetic groupc) Natural or Synthetic groupd) Fiber groupAns : (a)

14. Which of the following are piezo electric substances?1. Barium titanate2. Lead titanate3. Lead Zirconate4. Cadmium and sulphatea) 1,2 and 4b) 1,3and4c) 1,2and 3d) 2,3and 4Ans : (c)

15. Piezo-electric transducers area) Passive transducersb) Inverse transducersc) Digital transducersd) Pulse transducersAns : (b)

16. Piezo – electric transducers work when we apply _____________ to it.a) Mechanical forceb) Vibrationsc) Illuminationsd) HeatAns : (d)17. Piezo electric crystal can produce an emfa) When external mechanical force is applied to ib) When radiant energy stimulates the crystalc) When external magnetic field is appliedd) When the junction of two such crystals are heatedAns : (a)

18. The draw backs of strain gauges areS1: Low fatigue lifeS2: They are expensive, brittle and sensitive to temperatureS3: Poor linearitya) S1 and S2b) S2 and S3c) S1 and S3d) S1 onlyAns : (b)

19. LVDT windings are wound ona) Steel sheetsb) Aluminiumc) Ferrited) CopperAns : (c)

20. The size of air cored transducers in comparison to the iron core parts isa) Smallerb) Largerc) Samed) UnpredictableAns : (b)

21. The principle of operation of LVDT is based on the variation ofa) Self inductanceb) Mutual inductancec) Reluctanced) PermanenceAns : (b)

22. LVDT is an/a ___________ transducera) Magneto-strict ionb) Inductivec) Resistived) Eddy currentAns : (d)

23. Which of the following can be measured with the help of piezo electric crystal?a) Forceb) Velocityc) Soundd) PressureAns : (a)

24. S1: Transducer is a device which converts physical into electrical quantityS2: Transducer is also called as sensor.a) S1 is true & S2 is falseb) S2 is true & S1 is falsec) Both S1 & S2 are trued) Both S1 & S2 are falseAns (c)

27. In a LVDT, the two secondary voltagesa) Are independent of the core positionb) Vary unequally depending on the core positionc) Vary equally depending on the core positiond) Are always in phase quadratureAns : (b)

28. Capacitive transducers are normally employed for___________ measurementsa) Staticb) Dynamicc) Transientd) Both static and dynamicAns : (b)

29. Match the following1. EEG A. Diagnostic tool for heart alignment2. ECG B. Diagnostic tool for brain alignment3. Sphygmo-manometer C. Instrument used for measuring blood pressure4. Stethoscope D. instrument used to hear pulse/heart beata) 1- B, 2 – A, 3 – C, 4 – Db) 1 – B, 2 – A, 3 – D, 4 – Cc) 1- C, 2 – A, 3 – B, 4 – Dd) 1 – A, 2 – B, 3 – C, 4 – DAns : (a)

30. Pick the correct statement regarding functions of a transducerS1: Sense the magnitude, change in & / or frequency of same measurandS2: To provide electrical output that furnishes accurate, quantitative data about the measuranda) S1 is true & S2 is falseb) S2 is true & S1 is falsec) Both S1 & S2 are trued) Both S1 & S2 are falseAns : (c)

31. The transducers which requires an external power and their output is a measure of some variation such as resistance, inductance, capacitance etc., are called asa) Active transducerb) Primary sensorc) Passive transducerd) Self generating transducerAns : (c)

32. The principle of operation of variable resistance transducer isa) Deformation leads to change in resistanceb) Displacement of a contact slider on a resistancec) Coupling of two coils changes with displacementd) Movement of magnetic field produces variation in resistance of materialAns : (b)

33. The application of LVDT isa) Joint motionb) Finger movementc) Limb movementd) Heart wall motionAns : (c)

34. Venturi is associated witha) Venous blood pressureb) Digital plethysmographyc) Dialysate flow in artificial kidneyd) Blood flow in heart lung machineAns : (d)

35. Pressure transducer for measuring blood pressure isa) Strain gauge transducer onlyb) Strain gauge or capacitive transducerc) Resistive transducerd) Fiber optic transducerAns : (b)

36. The change in resistance of a metal wire owing to strain is due toS1: Change in dimension of wire expressed by factor (1-2µ)S2: Change in resistance ??a) S1 is true & S2 is falseb) S2 is true & S1 is falsec) Both S1 & S2 are trued) Both S1 & S2 are falseAns : (b)

37. In foil strain gauge the thickness of foil varies froma) 2.5 micron to 6 micronb) 25 micron (or) lessc) 25 micron to 60 micrond) 2.5 micron to 5 micronAns : (a)38. Photo conductive cell consists of a thin film ofa) Quartzb) Lithium sulphatec) Barium titanated) SeleniumAns : (d)

39. S1: In multimode fiber optics, intensity modulating schemes can be employed.S2: Schemes using polarizing techniques need birefringent fiber.a) S1 is true and S2 is falseb) Both S1 and S2 are truec) S1 is false and S2 is trued) Both S1 and S2 are falseans (b)

40. Test electrode is also known asa) Indicator electrodeb) Reference electrodec) Second electroded) Primary electrodeAns : (a)

41. Most commonly used indicator electrode isa) Calomel electrodeb) Silver electrodec) Silver – Silver chloride electroded) Glass electrodeAns : (d)

42. _____________ is the example of photo emissive cella) LDRb) Photo diodec) Photo transistord) Photo multiplier

Ans : (a)

43. pH value of venous blood isa) 7.30b) 7.40c) 7.35d) 7.45Ans : (c)

44. Silver chloride electrode is used as a reference electrode due to itsa) Large half cell potentialb) Stable half cell potentialc) Stable resting potentiald) Stable action potentialAns : (b)

45. The capacitance microphone is used for the detection ofa) Heart rateb) Blood flowc) Heart soundd) Foot pressureAns : (c)

46. In a graded index fiber, the total reflected light takes a ___________a) Straight line pathb) Parabolic pathc) Elliptical pathd) Circular pathAns (b)

47. ____________ fiber is used in interferometric instruments.a) Monomodeb) Multimodec) Birefringentd) CoatedAns (a)

48. Fiber optic sensor can be used to sense _________a) Displacementb) Powerc) Currentd) ResistanceAns (a)

49. Photo multiplier consists ofa) 1 Photo emissive cathode & 2 dynodesb) 2 Photo emissive cathodes & 2 dynodesc) 2 Photo emissive cathodes & 1 dynoded) 1 Photo emissive cathode & 1 dynodeAns : (a)

50. The resistance of LDR ________________ when exposed to radiant energy.a) Remains unalteredb) Increasesc) Reaches maximumd) DecreasesAns : (d)