Module 1
This set of Engineering Metrology Multiple Choice Questions & Answers (MCQs) focuses on “Line Standard
a) Yard
b) Meter
c) Precision scale
d) Length bar
View Answer
Answer: d
Explanation: Length bar is an end standard. Yard, meter and precision scale are line standards.
What are the functional dimensions?
1. What are the functional dimensions?
a) Have to be machined and fit with other mating components
b) Which have no effect on the performance of quality
c) Need not to be machined to an accuracy of the high degree
d) Function is more important than accuracy
View Answer
Answer: a
Explanation: Non-functional dimensions have no effect on the performance of quality of the assembly or component. Non-functional dimensions need not to be machined to higher accuracy.
Which of the following is true for uses of comparators
a) Can’t be used in mass production
b) Not suitable for inspection purposes
c) Can be used as working gauge
d) Slow rate of working
View Answer
Answer: c
Explanation: Comparators are used in mass production where components are checked at a fast rate. These can be used as inspection purposes, laboratory standards and working standards or gauges.
Measurement system and basic concepts of measurement methods
Ans-
The degree of closeness of the measured value of a certain quantity with its true value is known as
ANS-1
What is the length of the Imperial standard yard?
a) 38 m
b) 38 mm
c) 38 inches
d) 38 cm
View Answer
Answer: c
Explanation: The imperial standard yard is a bar made of bronze of 1 inch square cross section. It is 38 inches long.
Which of the following is not true for hole and shaft basis systems?
a) Hole basis system is generally preferred over shaft basis system
b) Shaft basis system can be used when products are made from bright drawn bars
c) Choice of the system depends upon nature of the product
d) In hole basis system, allowances are applied to the hole
View Answer
Answer: d
Explanation: Hole basis system is preferred because it is easy to produce a shaft with specified tolerances than hole. In hole basis system, all tolerances are applied to shaft and hole size is taken as basic size.
What is the principle of ‘The Johansson Mikrokator
a) Button spinning on a loop of string
b) Principle of interference
c) Optical magnification
d) Principle of transformer
View Answer
Answer: a
Explanation: Johansson Mikrokator is a mechanical comparator used to obtain mechanical magnification. Principle of Johansson Mikrokator is ‘spinning of a button on a loop string’. Magnification of this comparator is of the order of 5000.
The minimum number of wattmeter(s) required to measure 3 – phase, 3 – wire balanced or unbalanced power is
Option 2 : 2
Error of measurement =
ANS-1
Which of the following is incorrect about line standard?
a) These are legal standards
b) A round recess, half inch away from the ends is cut at both ends
c) Slope at the ends is zero
d) Points of supports are called ‘Airy’ points
View Answer
Answer: b
Explanation: A round recess is cut at both ends up to the central plane of the bar. These are one inch away from two ends.
Why tolerances are given to the parts
a) Because it’s impossible to make perfect settings
b) To reduce weight of the component
c) To reduce cost of the assembly
d) To reduce amount of material used
View Answer
Answer: a
Explanation: Tolerances are provided to the parts because variations in the material properties introduce errors and production machines themselves have inherent inaccuracies. Another reason to introduce tolerance is that it is not possible to make perfect settings by operator so some tolerances are provided.
From which category ‘Sigma comparator’ belongs?
a) Optical comparator
b) Mechanical comparator
c) Mechanical-optical comparator
d) Pneumatic comparator
View Answer
Answer: b
Explanation: Sigma comparator is a mechanical comparator. Components of sigma comparator are a plunger, knife edge, cross strip hinge, Y-shaped arm, driving drum, slit diaphragm, a scale and a pointer etc.
In a PMMC instrument, the swamping resistor is used to
Option 3 : Compensate for temperature variations
The ability by which a measuring device can detect small differences in the quantity being measured by it, is called its
ANS--2
Which of the following option is correct about straight edges?
a) Deflection be minimum at the centre
b) Deflection be maximum at the centre
c) Deflection be minimum at right most part
d) Deflection be minimum at left most part
View Answer
Answer: a
Explanation: For straight edges, minimum deflection at centre is desirable. For this, the support should be 0.554 L apart, where L is length of the bar.
Which of the following is not correct about plain gauges?
a) Used to check threaded portions
b) There is no scale in plain gauges
c) Indicates actual value of the inspected dimension
d) Can be used to check dimension of manufactured part
View Answer
Answer: c
Explanation: These gauges do not have any scale. These gauges are used only for determining that the inspected part is within a specified limit or not. They do not use to indicate actual value. Plain gauges are mostly used to check unthreaded shafts and holes.
Which of the following is not correct for pneumatic comparator?
a) Independent of operator skill
b) Loss of accuracy due to gauge wear
c) Speedy operation
d) Total life cost is less
View Answer
Answer: b
Explanation: In pneumatic comparator, there is no physical contact with setting gauge or part being measured. Due to this reason, there is no loss of accuracy due to gauge wear. It is an accurate, universal, reliable and speedy device.
The dielectric loss of a capacitor can be measured by which one of the following?
Option 2 : Schering bridge
The following term(s) is (are) associated with measuring devices
ANS--3
By which material metre (line standard) bar is made of?
a) Bronze
b) Platinum
c) Platinum-bronze alloy
d) Platinum-iridium alloy
View Answer
Answer: d
Explanation: Yard is made up of bronze bar. This bar is made of platinum-iridium alloy in which 90% is platinum and 10% iridium. Meter is the distance between two lines which are engraved on a bar surface.
Which of the following option is incorrect about interchangeability?
a) Increase output
b) Increase cost of production
c) Useful in mass production
d) Assembly time increases
View Answer
Answer: d
Explanation: An interchangeable part is one that can be replaced with a similar part manufactured to the same drawing. It can be used in mass production with an economic oriented approach. Assembly time decreases as mating parts are interchangeable.
What is the order of magnification in flow type pneumatic gauge?
a) 100 to 1000 times
b) 500 to 5000 times
c) 50 to 500 times
d) 100 to 2000 times
View Answer
Answer: b
Explanation: Velocity type pneumatic gauge have quick response. It can permit a large clearance between object surface and nozzle which results in less wear in gauging members. Less air consumption. So, the magnification of the order to 500-5000 times is possible.
Resistance can be measured using:
Option 4 : Ohmmeter
To compare an unknown with a standard through a calibrated system is called
ANS-2