Instrumentation Multiple Choice Questions Answers PDF

21. Consider the following statements:

1. The main shortcomings of diaphragms are that they are prone to shock vibrations.
2. Diaphragms have the advantages of high accuracy and good dynamic response.
3. Selection of material for diaphragms mainly depends upon temperature range and chemical nature of fluid coming in contact with diaphragm during pressure measurement.

Which of the above statements is/are correct?
(a) 1, 2 and 3.
(b) 2 and 3 only.
(c) 1 only.
(d) 1 and 2 only.

22. If the number of bellows elements is made double and the thickness of the bellows element is made half, the displacement of the element for the same applied pressure would be the

(a) 16 times.
(b) 4 times.
(c) same.
(d) one-fourth.

23. Bourdon tubes are made of

(a) copper.
(b) aluminum.
(c) metal alloys.
(d) phosphorus.

24. Rotameter is used for measuring

(a) flow.
(b) viscosity.
(c) specific gravity.
(d) none of these.

25. The meter measuring total flow in a liquid makes use of

(a) planti meter.
(b) variable area meter.
(c) square root extractor.
(d) none of the above.

26. Consider the following units for the measurement of pressure directly:

1. Rolta meter. 2. Bourdon tube. 3. Planti meter. 4. Vanes.

Of these, the pressure can be measured by
(a) 1 and 2 only.
(b) 3 and 4 only.
(c) 2 only.
(d) 1, 2, 3 and 4.

27. The instrumentation amplifiers are used principally to amplify signals from which of the following?

(a) Transducers.
(b) Active flitters.
(c) Choppers.
(d) D/A converters.

28. Self-generating type transducers are………..transducers.

(a) active
(b) passive
(c) secondary
(d) inverse

29. Which one of the following is not a self-generating type transducer?

(a) Thermocouple and thermopile.
(b) Piezoelectric pick-up.
(c) Photovoltaic cell.
(d) Magnetostriction gauge.

30. The transducer that converts the input signal into the output signal, which is a continuous function of time, is known as………transducers.

(a) active
(b) passive
(c) analog
(d) digital

31. A transducer that converts measurand into the form of pulse is called the………..transducers.

(a) active
(b) analog
(c) digital
(d) pulse

32. Which one of the following is a passive transducer ?

(a) Piezoelectric.
(b) Thermocouple.
(c) Photovoltaic cell.
(d) LVDT.

33. Which one of the following transducers is an active transducer ?

(a) Piezoelectric pressure transducer.
(b) Metallic strain gauge.
(c) Semiconductor strain gauge.
(d) Platinum resistance thermometer.

34. The lower limit of useful working range of a transducer is determined by

(a) minimum useful input level.
(b) transducer error and noise.
(c) cross-sensitivity.
(d) dynamic response.

35. Which of the following transducers is classified as an active transducer ?

(a) Metallic strain gauge.
(b) Capacitive microphone.
(c) LVDT.
(d) Piezoelectric transducer.

36. Pair of active transducers is

(a) Thermistor, Solar cell.
(b) Thermocouple, Thermistor.
(c) Thermocouple, Solar cell.
(d) Solar cell, LVDT.

37. Consider the following transducers :

1. LVDT. 2. Piezoelectric. 3. Thermocouple.
2. Photovoltaic cell. 5. Strain gauge.

Which of these are active transducers ?
(a) 1, 2 and 5.
(b) 1, 3 and 4.
(c) 2, 3 and 5.
(d) 2, 3 and 4.

38. In a resistance potentiometer, the nonlinearity

(a) decreases with the increase in ratio of potentiometer to load resistance.
(b) increases with the increase in ratio of potentiometer to load resistance.
(c) is independent of the ratio of potentiometer to load resistance.
(d) none of the above.

39. Resolution of a potentiometric transducer depends on

(a) diameter of wire
(b) length of wire.
(c) material of wire.
(d) excitation voltage.

40. High value pot resistance leads to

(a) low sensitivity.
(b) high sensitivity.
(c) low nonlinearity.
(d) less error.