This Portion of Electrical and Electronic Measurements and Measuring instruments contains Measurements and Measurement Systems MCQs (Multiple Choice Questions and Answers) / Objective Type Questions and Answers.
This Section covers below lists of topics.
- Measurements
- Significance of measurements
- Methods of Measurements
- Instruments and measurement system
- Mechanical, Electrical and Electronic instruments
- Deflection and Null Type Instruments
- Analog and Digital Modes of Operation
- Function of instruments and Measurement Systems
- Application of measurement systems
- Types of instrumentation systems
- Information and Signal Processing
- Elements of Generalized measurement System
- Input / Output Configuration of Measuring instruments and Measurement Systems
- Methods of Correction for interfering and modifying Inputs
PRACTICE IT NOW TO SHARPEN YOUR CONCEPT AND KNOWLEDGE
1. The measurement of a Quantity
- is an act of comparison of an unknown Quantity with another Quantity
- is an act of comparison of an unknown quantity with a known quantity whose accuracy may be known or may not be known
- is an act of comparison of an unknown quantity with a predefined acceptable standards which is accurately known
- none of the above
C. is an act of comparison of an unknown quantity with a predefined acceptable standards which is accurately known
2. In Present Day measurement Systems
- Direct Methods are commonly used
- Use of Direct Method is limited but indirect methods are commonly used
- Both direct and indirect methods are commonly used
- All of the above
B. Use of Direct Method is limited but indirect methods are commonly used
3. Purely mechanical instruments cannot be used for dynamic measurement because they have:
- high inertia
- large time constant
- higher response time
- All the above
D. All the above
4. The use of electronic instruments is becoming more expensive because they have
- a high sensitivity and reliability
- a fast response and compatibility with digital computers
- the capability to respond to signals from remote places
- All of the above
D. All of the above
5. A null type of instruments as compared to deflection type instrument has
- a higher accuracy
- a lower sensitivity
- a faster response
- all of the above
A. a higher accuracy
6. in an intelligent information system used for the measurement of a physical quantity
- the digital computer must perform all or nearly all the signal and information processing
- the observer must perform all or nearly all the signal and information processing
- the digital computer is not required
- none of the above
A. the digital computer must perform all or nearly all the signal and information processing
7. In a generalized measurement system, the function of the signal manipulating element is to
- change the quantity under measurement to an analogous signal
- Change the magnitude of the input signal while retaining its identity
- to perform linear operations like filtering and multiplication
- to perform non linear operations like filtering chopping and clipping and clamping
- none of the above
B. Change the magnitude of the input signal while retaining its identity
8. A Modifying input to a measurement system can be defined as an input
- which changes the input output relationship for desired inputs only
- which changes the input-output relationship for desired as well as interfering inputs
- which changes the input-output relationship for interfering inputs only
- None of the above
B. which changes the input-output relationship for desired as well as interfering inputs
9. In a Measurement System, the open loop transfer function is 10 and changes by 10 percent .if a closed loop system is adopted wherein the feedback system has a transfer function of 100. What will be the changes in output in the case of open loop and in closed loop systems?
- 10%, 10×10-3%
- 10%, 1×10-3%
- 100%, 10×10-3%
- 100%, 1×10-3%
A. 10%, 10×10-3%
10. In a permanent magnet moving coil type of ammeter, the current is I=kθ/NBA Where θ=deflection, k=spring constant, N=numbers of turns of moving coil and B=flux density of the field produced permanent magnet .Temperature is an interfering input to the system. It is known that strength of magnets reduces by 0.02 per cent per °C and the strength of springs reduces by 0. 4 Percent per °C. Which methods should be adopted to apply corrections for the interfering input?
- Method of inherent insensitivity
- Method of high gain feedback
- Method of calculated output corrections
- Method of opposing inputs
C. Method of calculated output corrections
11. A null-type instrument as compared to a deflection-type instrument has
- a lower sensitivity
- a faster response
- a higher accuracy
- all of the above
C. a higher accuracy
12. In a measurement system, the function of the signal manipulating element is to
- change the magnitude of the input signal while retaining its identity
- change the quantity under measurement to an analogous signal
- to perform non-linear operation like filtering, chopping and clipping and clamping
- to perform linear operation like addition and multiplication
A. change the magnitude of the input signal while retaining its identity
13. The measurement of a quantity
- is an act of comparison of an unknown quantity with a predefined acceptable standard which is accurately known
- is an act of comparison of an unknown quantity with another quantity
- is an act of comparison of an unknown quantity with a known quantity whose accuracy may be known or may not be known
- none of these
A. is an act of comparison of an unknown quantity with a predefined acceptable standard which is accurately known
14. Purely mechanical instruments cannot be used for dynamic measurements because they have
- large time constant
- higher response time
- high inertia
- all of the above
D. all of the above
15. A modifying input to a measurement system can be defined as an input
- which changes the input–output relationship for desired as well as interfering inputs
- which changes the input–output relationship for desired inputs only
- which changes the input–output relationship for interfering inputs only
- none of the above
A. which changes the input–output relationship for desired as well as interfering inputs
16. In measurement systems, which of the following static characteristics are desirable?
- Sensitivity
- Accuracy
- Reproducibility
- All of the above
D. All of the above
17. In measurement systems, which of the following are undesirable static characteristics?
- Reproducibility and nonlinearity
- Drift, static error and dead zone
- Sensitivity and accuracy
- Drift, static error, dead zone and nonlinearity
D. Drift, static error, dead zone and nonlinearity
18. In some temperature measurement, the reading is recorded as 25.70°C. The reading has
- five significant figures
- four significant figures
- three significant figures
- none of the above
B. four significant figures
19. In the centre of a zero analog ammeter having a range of -10 A to +10 A, there is a detectable change of the pointer from its zero position on either side of the scale only as the current reaches a value of 1 A (on either side). The ammeter has a
- dead zone of 1 A
- dead zone of 2 A
- resolution of 1 A
- sensitivity of 1 A
B. dead zone of 2 A
20. A dc circuit can be represented by an internal voltage source of 50 V with an output resistance of 100 kW. In order to achieve 99% accuracy for voltage measurement across its terminals, the voltage measuring device should have
- a resistance of at least 10 W
- a resistance of 100 kW
- a resistance of at least 10 MW
- none of the above
C. a resistance of at least 10 MW
21. In ac circuits, the connection of measuring instruments cause loading errors which may affect
- only the phase of the quantity being measured
- only the magnitude of the quantity being measured
- both the phase and the magnitude of the quantity
- magnitude, phase and also the waveform of the quantity being measured
D. magnitude, phase and also the waveform of the quantity being measured
22. A pressure gauge is calibrated form 0–50 kN/m2. It has a uniform scale with 100 scale divisions. One fifth of the scale division can be read with certainty. The gauge has a
- dead zone of 0.2 kN/m2
- resolution of 0.1 kN/m2
- resolution of 0.5 kN/m2
- threshold of 0.1 kN/m2
B. resolution of 0.1 kN/m2
23. A pressure measurement instrument is calibrated between 10 bar and 260 bar. The scale span of the instrument is
- 10 bar
- 260 bar
- 250 bar
- 270 bar
C. 250 bar
24. A Wheatstone bridge is balanced with all the four resistances equal to 1 kW each. The bridge supply voltage is 100 V. The value of one of the resistance is changed to 1010 W. The output voltage is measured with a voltage measuring device of infinite resistance. The bridge sensitivity is
- 2.5 mV/W
- 10 V/W
- 25 mV/W
- none of the above
C. 25 mV/W
25. The main advantage of the null balance technique of measurement is that
- it gives a quick measurement
- it does not load the medium
- it gives a centre zero value at its input
- it is not affected by temperature variation
B. it does not load the medium
26. The smallest change in a measured variable to which an instrument will respond is
- resolution
- precision
- sensitivity
- accuracy
A. resolution
27. The desirable static characteristics of a measurement are
- precision
- accuracy
- sensitivity
- all of these
D. all of these
28. The errors mainly caused by human mistakes are
- Systematic error
- Instrumental error
- Observational error
- Gross error
D. Gross error
29. Systematic errors are
- environmental error
- observational error
- instrumental error
- all of the above
D. all of the above
30. An analog ammeter is
- an absolute instrument
- an indicating instrument
- a controlling instrument
- a recording instrument
B. an indicating instrument
