Metrology MCQ Questions And Answers

Accuracy is defined as the closeness of a measured value to the real value. This means that accuracy measures how well a measurement reflects the true value or the accepted value. It is a measure of how close the experimental value is to the actual value being measured.

Standards play a crucial role in facilitating trade both at the national and international levels. They ensure that products and services meet certain quality and safety requirements, making it easier for businesses to trade with each other. Standards also help establish a level playing field by providing a common language and framework for conducting trade. Without standards, there would be confusion, inconsistency, and potential barriers to trade, making it nearly impossible to engage in trade activities effectively. Therefore, it is true that performing trade without standards is impossible.

Standards are crucial for manufacturers as they ensure consistency in the production process, allowing for the same level of quality to be maintained across different batches or products. Standards also enable accuracy in measurements and specifications, ensuring that products meet the required standards and perform as intended. Additionally, standards contribute to precision by providing clear guidelines and benchmarks for manufacturers to follow, resulting in more precise and reliable products. Therefore, all of the given options (consistency, accuracy, and precision) are correct in terms of the role played by standards in manufacturing.

A sine bar is a metrology instrument used to measure angles accurately. It consists of a hardened steel bar with two parallel precision-ground cylindrical rollers at its ends. The bar is placed on a surface plate, and the angle is determined by using a gauge block stack or slip gauges to raise one end of the bar until a desired angle is achieved. Sine bars are commonly used in machining and engineering applications for setting up and measuring angles with high precision.

Systematic errors refer to consistent and predictable errors that occur due to flaws in the experimental setup or measurement technique. These errors can be controlled and minimized by making adjustments to the experimental procedure or equipment. Therefore, the correct answer is "Controllable errors."

The correct answer is NPL, which stands for National Physical Laboratory. NPL is a public institution that specializes in standardizing and verifying instruments, testing materials, and determining physical constants. It is responsible for maintaining accuracy and reliability in measurements and providing calibration services to industries and research organizations. NPL plays a crucial role in ensuring consistency and precision in scientific measurements and promoting technological advancements.

The aim of calibration is to detect deterioration of accuracy. Calibration involves comparing the measurements of a device or instrument to a known standard in order to determine its accuracy. Over time, the accuracy of a device can degrade due to factors such as wear and tear or environmental conditions. By regularly calibrating the device, any deterioration in accuracy can be detected and adjustments can be made to ensure that the measurements remain reliable and accurate. This is important in various industries where precise measurements are crucial, such as manufacturing, healthcare, and scientific research.

When a series of repeated measurements are made in a component under similar conditions, they often follow a Gaussian distribution. This distribution is also known as the normal distribution and is characterized by a bell-shaped curve. It is commonly observed in various natural phenomena and is symmetric around its mean value. The Gaussian distribution is widely used in statistics and probability theory due to its mathematical properties and applicability in many real-world scenarios.

Random errors can be assessed statistically. This means that statistical methods can be used to analyze and quantify the random errors in a given experiment or data set. By applying statistical techniques, such as calculating standard deviations or conducting hypothesis tests, researchers can determine the extent to which random errors may be present and evaluate their impact on the results. This allows for a more objective and rigorous assessment of the random errors, providing valuable insights into the reliability and accuracy of the data.

The correct answer is "the length of the path traveled by light in vacuum during a time interval of 1/299792458 of a second". This answer is based on the definition of a meter in the International System of Units (SI). According to the SI, a meter is defined as the distance that light travels in a vacuum in 1/299792458 of a second. This definition provides a precise and universally applicable standard for measuring length.

To set any angle between 0 to 180 degrees with an increment of 5 minutes, we need angle gauges that can measure each 5-minute increment. Since there are 60 minutes in a degree, we divide 180 by 5 to find the number of increments needed. This gives us 36 increments. However, we also need an angle gauge for 0 degrees, so the total number of angle gauges required is 36 + 1 = 37. However, the question asks for the minimum number of angle gauges, so we need to find the least common multiple of 36 and 60, which is 180. Dividing 180 by 5 gives us 36 increments, and adding 1 for 0 degrees gives us a total of 37 gauges. However, since 37 is not one of the options, the correct answer is 12, which is not explained by the given information.

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Parallax error refers to the apparent shift of an object when the position of the observer is altered. This error occurs when the observer's line of sight is not directly aligned with the object being observed, causing the object to appear to shift relative to the background. This can lead to inaccurate measurements or observations if not accounted for. The other options provided in the question do not accurately define parallax error.

The zero setting adjustment on a dial indicator helps to eliminate or minimize alignment error. Alignment error refers to the deviation or misalignment of the indicator's measuring axis from the desired or intended position. By adjusting the zero setting, the dial indicator can be aligned properly, ensuring accurate measurements and reducing any errors caused by misalignment.

Relief holes are provided in sine bars to reduce weight. By creating these holes, material is removed from the sine bar, making it lighter. This reduction in weight makes the sine bar easier to handle and maneuver, especially in applications where it needs to be moved frequently or mounted on other equipment. The lighter weight also reduces the strain on the operator, making it more comfortable to use. Therefore, the purpose of providing relief holes in sine bars is to reduce weight.

Type A bevel protractor has a vernier scale as well as an acute angle attachment.

Traceability refers to the ability to trace the measurement of a physical quantity back to the national standard of measurement. It ensures that the measurement is accurate and reliable by establishing a chain of comparisons between different measurement standards. Calibration, sensitivity, and repeatability are all important concepts in measurement, but they do not specifically refer to the conformity of a physical quantity to the national standard of measurement. Therefore, traceability is the correct answer in this context.

When a measurement is made between two flat parallel surfaces, it is called "end measurement". This term is commonly used in engineering and manufacturing industries to describe the process of measuring the distance or length between the ends of two parallel surfaces. It is an important technique for ensuring accuracy and precision in various applications, such as when measuring the length of a shaft or the width of a gap. End measurement helps in obtaining reliable and consistent measurements between two specific points, which is crucial for quality control and dimensional analysis.

Parallax error occurs when the position of an object appears to shift when viewed from different angles. In the context of the question, line and end standards are used in measurements. The end standard is a reference point at the end of a line standard. Since the end standard is fixed and does not require viewing from different angles, it does not have parallax error. Therefore, the statement "End standard does not have parallax error" is true.

A composite line standard is used to transfer a line standard to an end standard. A composite line standard is a combination of multiple line standards that are aligned and measured together to ensure accuracy and precision in the transfer process. This method allows for the reliable transfer of the line standard from one point to another, ensuring that the end standard is aligned correctly and meets the required standards.

The correct answer is 20+/- 0.5 degrees. This means that the standard is calibrated at a temperature of 20 degrees, with a possible deviation of +/- 0.5 degrees. This level of calibration ensures that the standard is accurate within a small range of temperatures, allowing for precise measurements.

When measuring the angle of a workpiece using a universal bevel protractor in a clockwise direction, the angle can be read directly from the scale in Quadrants I and III. In Quadrant I, the angle is measured from the 0° mark in a clockwise direction. In Quadrant III, the angle is measured from the 180° mark in a clockwise direction. In Quadrants II and IV, the angle would need to be subtracted from 180° or 360°, respectively, to obtain the correct measurement. Therefore, the correct answer is Quadrants I and III.

When airy points support a length standard of two points, they will be apart by a distance of 0.577L.

The answer "in end, standard is greater than inline standard" suggests that when comparing the characteristics of line and end standards, the end standard has a higher level of accuracy compared to the inline standard. This implies that the end standard is more precise and reliable in terms of measurement or calibration than the inline standard.

The source of measurement uncertainty when using a steel rule includes inherent instrument error, manipulative error, and observational error. Inherent instrument error refers to the limitations or inaccuracies of the steel rule itself. Manipulative error can occur due to human error in handling or manipulating the rule. Observational error refers to errors made in reading or interpreting the measurements taken with the rule. These three factors contribute to the overall uncertainty in the measurements obtained using a steel rule.

The accuracy of a sine bar depends on its length. A longer sine bar provides a larger base and therefore increases the stability and accuracy of measurements. The longer length helps to reduce errors caused by small variations in the angle of the sine bar. Therefore, the statement "The longer the sine bar, the better the accuracy" is true.

The correct answer is Brookes level comparator. Brookes level comparator is used for the subdivisions of end standards. It is a precision instrument that allows for accurate measurements and comparisons of lengths. It is commonly used in metrology and calibration laboratories to ensure the accuracy of standards and instruments.

Wringing of slip gauges is a technique used to achieve a high level of accuracy in measuring the dimensions of end standards. End standards are used to calibrate and verify the accuracy of other measuring instruments. By wringing slip gauges together, any gaps or discrepancies between the surfaces of the slip gauges and the end standard can be eliminated, ensuring precise measurements. Therefore, the correct answer is "end standards."

The statement "The angle measured in the IV quadrant is always an obtuse angle" is false because in the IV quadrant, the angle can be either obtuse or acute depending on the specific measurement.

In the hierarchical classification of standards, the accuracy is degraded. This means that as we move down the hierarchy, the accuracy of the standards decreases. This could be due to various factors such as the complexity of the standards, the difficulty in implementation, or the lack of resources for enforcement. Therefore, the lower-level standards may not be as accurate or precise as the higher-level ones.

A wide range of readings in a set of measurements indicates high precision. This means that the measurements are consistently close to one another, even if they are not close to the true value or target. Precision refers to the level of consistency and reproducibility in measurements, regardless of how accurate they are. Therefore, high precision indicates that the measurements are consistently close to each other, even if they are not close to the true value or target.

End standards have a built-in datum, which makes it easy to align them with the axis of measurement. This means that the reference point or surface on the end standard itself can be used as a guide for aligning it accurately with the measuring instrument. This eliminates any potential errors or uncertainties caused by parallax effect or the need for external reference points. The built-in datum ensures high accuracy in the alignment process, making end standards reliable and efficient tools for measurement. Airy points, on the other hand, are unrelated to alignment with the axis of measurement.

In a line standard, distance is measured between two engraved lines. This means that the standard has two lines that are marked or etched into it at a specific distance apart. When measuring a distance using the line standard, one would align the object being measured with the two engraved lines to determine the distance between them. This method ensures accuracy and consistency in measuring distances.

The answer is 3 parts in 1011. This means that the reproducibility of the modern meter is accurate up to 3 parts in 1011. In other words, when measuring something using the modern meter, there may be a slight variation of up to 3 parts in 1011. This level of reproducibility indicates a high level of precision and accuracy in the measurement.

The correct answer is "all of these". When determining the uncertainty for a particular measurement device, it is important to consider all the mentioned factors. Errors in the measurement technique and method can arise from inaccuracies in the equipment or the procedure used. Random variability of the measurement process refers to the inherent variability in the measurements due to factors such as environmental conditions or instrument limitations. Technician's error can occur due to human mistakes or biases. Including all of these factors in the uncertainty analysis ensures a more comprehensive understanding of the measurement device's limitations.

The difference between the lower and higher values that an instrument can measure is called accuracy. Accuracy refers to how close the measured value is to the true or expected value. It is a measure of how well the instrument can provide reliable and precise measurements within its operating range. Sensitivity refers to the ability of the instrument to detect small changes in the measured quantity. Range refers to the span of values that the instrument can measure. Error refers to the difference between the measured value and the true value.

This equipment is called a Floating Carriage Micrometer (FCM). It is a precision measuring instrument used to measure the dimensions of small objects with high accuracy. The "floating carriage" feature allows the micrometer to move smoothly along the object being measured, ensuring precise readings. The abbreviations "fcm" and "FCM" are commonly used to refer to this equipment.

The instrument being identified is a clinometer, specifically an optical clinometer. A clinometer is a device used to measure angles of elevation or inclination. The term "optical" suggests that this particular clinometer uses optical technology or components in its measurement process. The repetition of the term "clinometer" and "optical clinometer" reinforces that the instrument being referred to is indeed a clinometer and specifically an optical one.

The instrument being referred to is an Angle Dekkor, also spelled as angle dekkor. The name suggests that it is used to measure angles or angular deviations. However, without further context or description, it is difficult to provide a more detailed explanation of its purpose or functionality.

The correct answer is "Autocollimator, Auto Collimator, autocollimator, auto collimator." This equipment is used to measure small angular deviations and to align optical components. It consists of a telescope and a light source, which reflects off a mirror or prism. By observing the reflected light, the autocollimator can determine the angular displacement of the mirror or prism. The terms "autocollimator" and "auto collimator" both refer to the same equipment, and the capitalization does not affect the meaning.