1. Which type of measurement error arises from fluctuations in environmental conditions during the measurement process?
a) Systematic error
b) Instrumental error
c) Random error
d) Human error
Correct answer: c) Random error
Explanation: Random errors are caused by unpredictable fluctuations in environmental conditions or inherent variability in the measurement process. They cannot be eliminated completely but can be minimized through repeated measurements and statistical analysis.
2. What is the primary characteristic of a dynamic measurement system?
a) It provides accurate measurements over a wide range of frequencies.
b) It is only suitable for measuring static quantities.
c) It does not require calibration.
d) It is unaffected by external disturbances.
Correct answer: a) It provides accurate measurements over a wide range of frequencies.
Explanation: Dynamic measurement systems are designed to accurately measure changing or dynamic quantities, such as signals varying with time or frequency, making them suitable for applications like waveform analysis and frequency response testing.
3. Which type of instrument error can be attributed to inconsistent interpretation or recording of measurement readings?
a) Random error
b) Systematic error
c) Instrumental error
d) Parallax error
Correct answer: d) Parallax error
Explanation: Parallax error occurs when the observer’s line of sight is not perpendicular to the scale being read, leading to inaccuracies in measurement due to an apparent shift in the position of the scale.
4. Which statistical analysis method is commonly used to estimate the magnitude of random errors in measurements?
a) Regression analysis
b) Analysis of variance (ANOVA)
c) Standard deviation calculation
d) Chi-square test
Correct answer: c) Standard deviation calculation
Explanation: Standard deviation is a statistical measure of the amount of variation or dispersion in a set of values. It provides an estimate of the magnitude of random errors in measurements by indicating how much individual measurements differ from the mean.
5. Which type of voltmeter is most suitable for accurately measuring rapidly changing voltage levels?
a) Peak responding voltmeter
b) Average responding voltmeter
c) RMS responding voltmeter
d) Multi-meter
Correct answer: a) Peak responding voltmeter
Explanation: Peak responding voltmeters are designed to quickly respond to and accurately measure the peak voltage levels of rapidly changing waveforms, making them suitable for applications such as peak voltage detection in electronic circuits.
6. What is the primary advantage of a chopper-type voltmeter over a solid-state voltmeter for DC voltage measurements?
a) Higher accuracy
b) Lower cost
c) Greater reliability
d) Reduced thermal EMF effects
Correct answer: d) Reduced thermal EMF effects
Explanation: Chopper-type voltmeters utilize a technique that minimizes thermal electromotive force (EMF) effects, resulting in more accurate DC voltage measurements, especially in high-precision applications where thermal effects can introduce significant errors.
7. Which type of instrument is specifically designed to measure the average power of an AC electrical signal?
a) RMS voltmeter
b) Power meter
c) Bolometer
d) Calorimeter
Correct answer: b) Power meter
Explanation: Power meters are instruments designed to measure the average power of an AC electrical signal accurately. They are commonly used in various applications, including power quality analysis, energy monitoring, and electronic circuit testing.
8. In which calibration method is the instrument under test compared directly with a standard reference instrument?
a) Ratio method
b) Substitution method
c) Comparison method
d) Transfer method
Correct answer: c) Comparison method
Explanation: In the comparison method of calibration, the instrument under test is directly compared with a standard reference instrument of known accuracy under controlled conditions. Any discrepancies between the measurements of the two instruments are used to calibrate the instrument under test.
9. Which type of AC voltmeter utilizes a rectifier for measurement purposes?
a) RMS voltmeter
b) Peak responding voltmeter
c) Average responding voltmeter
d) Multi-meter
Correct answer: c) Average responding voltmeter
Explanation: Average responding voltmeters utilize rectifiers to convert AC voltage into a proportional DC voltage, allowing them to measure the average value of the AC waveform. They are commonly used for general-purpose AC voltage measurements.
10. What is the primary function of a bolometer in measurement applications?
a) To measure radiation levels
b) To measure electrical resistance
c) To measure temperature changes
d) To measure pressure variations
Correct answer: a) To measure radiation levels
Explanation: Bolometers are devices designed to measure the power of incident electromagnetic radiation, typically in the form of infrared or microwave radiation. They are used in various applications, including astronomy, materials science, and environmental monitoring, for detecting and quantifying radiation levels.