# Engineering Metrology Mcqs

Q:

A) It is a number which is generally larger than 1 | B) Range – 2 to 7 |

C) Can be calculated by using MS excel | D) Depends on the selected coverage probability |

Answer & Explanation
Answer: B) Range – 2 to 7

Explanation: The coverage factor generally depends upon the probability distribution type of the output measurement quantity in the measurement model and on the selected coverage probability. Its range is generally between 2 to 3, can be more for special purposes.

Explanation: The coverage factor generally depends upon the probability distribution type of the output measurement quantity in the measurement model and on the selected coverage probability. Its range is generally between 2 to 3, can be more for special purposes.

95

Q:

A) T, F | B) F, F |

C) T, T | D) F, T |

Answer & Explanation
Answer: C) T, T

Explanation: In metrology industry, a typically estimate of uncertainty to 95.45% confidence and coverage factor where k=2 is used. It can vary according to requirement. Last calculation is generally the expanded uncertainty while estimating measurement uncertainty.

Explanation: In metrology industry, a typically estimate of uncertainty to 95.45% confidence and coverage factor where k=2 is used. It can vary according to requirement. Last calculation is generally the expanded uncertainty while estimating measurement uncertainty.

108

Q:

A) 2 | B) 2.89 |

C) 3 | D) 3.89 |

Answer & Explanation
Answer: D) 3.89

Explanation: In the manufacturing industry, the main aim is for a failure rate of 1 in ten thousand or a coverage factor ‘k’ of 99.99% confidence, where coverage factor = 3.89. However, Confidence intervals can be greater or smaller for different industries depending on acceptable failure rates.

Explanation: In the manufacturing industry, the main aim is for a failure rate of 1 in ten thousand or a coverage factor ‘k’ of 99.99% confidence, where coverage factor = 3.89. However, Confidence intervals can be greater or smaller for different industries depending on acceptable failure rates.

103

Q:

A) Student’s T table | B) F distribution table |

C) Wishart distribution table | D) Tau distribution table |

Answer & Explanation
Answer: A) Student’s T table

Explanation: Student’s T table is generally used to find coverage factor. The values are generally found at the bottom of the table especially the last row and it is generally marked with the infinity (∞) symbol.

Explanation: Student’s T table is generally used to find coverage factor. The values are generally found at the bottom of the table especially the last row and it is generally marked with the infinity (∞) symbol.

104

Q:

A) 95 % | B) 94 % |

C) 95.45 % | D) 94.45 % |

Answer & Explanation
Answer: C) 95.45 %

Explanation: Confidence interval for the value of coverage factor 2 is generally taken as 95 % but it is not the actual value. The actual value for this is 95.45 %. For 95 % confidence interval, actual ‘k’ or coverage factor is 1.96.

Explanation: Confidence interval for the value of coverage factor 2 is generally taken as 95 % but it is not the actual value. The actual value for this is 95.45 %. For 95 % confidence interval, actual ‘k’ or coverage factor is 1.96.

106

Q:

A) Arcsin distribution | B) Binomial distribution |

C) Poisson distribution | D) Bernoulli distribution |

Answer & Explanation
Answer: A) Arcsin distribution

Explanation: U-probability distribution of Type-B evaluation method of uncertainty is used when the values are at extreme limits and values are least at mean for example Arcsin distribution. Standard uncertainty = a/√2.

Explanation: U-probability distribution of Type-B evaluation method of uncertainty is used when the values are at extreme limits and values are least at mean for example Arcsin distribution. Standard uncertainty = a/√2.

118

Q:

A) Hysteresis | B) Common Mode Voltage |

C) Nonlinearity | D) Repeatability |

Answer & Explanation
Answer: D) Repeatability

Explanation: Resolution, Scale Size and Quantization, Hysteresis, Common Mode Voltage, Installation, Nonlinearity or Linearity, Spatial Variation, Loading uncertainties, Sensitivity and Zero offset, these all are Type-B uncertainties.

Explanation: Resolution, Scale Size and Quantization, Hysteresis, Common Mode Voltage, Installation, Nonlinearity or Linearity, Spatial Variation, Loading uncertainties, Sensitivity and Zero offset, these all are Type-B uncertainties.

71

Q:

A) Expanded uncertainty = Coverage factor * Combined uncertainty | B) Combined uncertainty = Coverage factor * Expanded uncertainty |

C) Coverage factor = Combined uncertainty * Expanded uncertainty | D) Coverage factor * Combined uncertainty * Expanded uncertainty = 1 |

Answer & Explanation
Answer: A) Expanded uncertainty = Coverage factor * Combined uncertainty

Explanation: The equation which is used to calculate expanded uncertainty is a very basic equation. To calculate expanded uncertainty, one will need to multiply a coverage factor by the combined uncertainty.

Explanation: The equation which is used to calculate expanded uncertainty is a very basic equation. To calculate expanded uncertainty, one will need to multiply a coverage factor by the combined uncertainty.

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