1. Deflection methods of direct measurements are most widely used as these are
(a) most simple.
(b) most accurate.
(c) least time consuming.
(d) most simple and least time consuming.
2. Comparison methods are used
(a) because these are most simple.
(b) because these are inexpensive.
(c) because these take least time in measurement.
(d) when a high accuracy of measurement is required.
3. The main advantage of the null balance technique of measurement is that
(a) it does not load the medium.
(b) it gives a centre zero value at its input.
(c) it gives quick measurement.
(d) it is not affected by temperature variation.
4. Consider the following statements in connection with deflection and null type instruments:
- Null type instrument is more accurate than the deflection type one.
- Null type of instrument can be highly sensitive as compared with deflection type
- Under dynamic conditions, null type instrument is not preferred to deflection type instrument.
- Response is faster in null type instrument as compared to deflection type instrument.
Which of these statements are correct?
(a) 1, 2 and 3 only.
(b) 1, 2 and 4 only.
(c) 2, 3 and 4 only.
(d) 1, 2, 3 and 4.
5. The region between the limits within which a quantity is measured received or transmitted, expressed by stating the lower and upper limits is called the
(c) range limit.
(d) none of these.
6. The span of a zero-centered voltmeter having a scale from – 10 V to + 10 V is
(a) 0 V
(b) – 10 V
(c) 10 V
(d) 20 V
7. If two meters X and Y require 40 mA and 50 mA respectively, to give full scale deflection, then
(a) X is more sensitive.
(b) Y is more sensitive.
(c) both X and Y are equally sensitive.
(d) it would not be possible to assess the sensitivity on the basis of the given data.
8. A meter having a sensitivity of 2 kΩ/V is used for the measurement of voltage across a circuit having an output resistance of 1 KΩ and an open circuit voltage of 8 V. What is the reading of the meter at its 10 V scale ?
(a) 5.72 V
(b) 6.51 V
(c) 7.62 V
(d) 7.91 V
9. The smallest change in a measured variable to which an instrument will respond is
10. Resolution of an instrument is
(a) the minimum quantity it can measure.
(b) the maximum quantity it can measure.
(c) the maximum nonlinearity.
(d) ability to distinguish polarity.
11. Hysteresis in an instrument means
(a) the change in same reading when input is first increased and then reduced.
(b) the reliability of the instrument.
(c) the repeatability of the instrument.
(d) the inaccuracy due to change in temperature.
12. The static error band of an instrument implies the
(a) accuracy of the instrument.
(b) irrepeatability of the instrument.
(c) error caused when the pen is stopped at some deflection.
(d) error introduced in low varying inputs.
13. The static error band of an instrument does not include
(b) electrical drift.
(c) hysteresis in the instrument.
(d) none of the above.
14. The fact as to how closely the instrument reading follows the measured variables is called the
15. An higher scale ammeter is used to measure too low current. The measurement would have low
(d) all of these.
16. Thermal zero-shift in an instrument refers to
(a) maximum variation in pen zero due to temperature variation.
(b) inaccuracy in measurement due to temperature variation.
(c) shift in zero adjustment due to expansion of springs due to temperature variation.
(d) none of the above.
17. In which part of the scale does the pointer indicate most accurately?
(a) In the first third of the scale.
(b) In the first half of the scale.
(c) In about middle of the scale.
(d) In the last third of the scale.
18. When reading is taken at half scale in the instrument, the error is
(a) exactly equal to half of full-scale error.
(b) equal to full-scale error.
(c) less than full-scale error.
(d) more than full-scale error.
19. The reliability of a measuring instrument means
(a) the life of the instrument.
(b) the extent over which the characteristics remain linear.
(c) degree to which repeatability continues to remain within specified limits.
(d) all of these.
20. Undesirable characteristics of a measurement system are
(a) accuracy and repeatability.
(b) static error.
(c) drift and dead zone.
(d) both (b) and (c).