# Engineering Metrology Questions and Answers – Caliper Principle

This set of Engineering Metrology Multiple Choice Questions & Answers (MCQs) focuses on “Caliper Principle”.

1. Why is the caliper principle used?
a) For circular divisions
b) For checking flatness
c) For measuring dimensions with vernier caliper
d) For measuring dimensions with micrometer

Explanation: Caliper principle is used for the circular division or to divide a circular disc in number of divisions. Circular division deals with the continuous division of a Circle and measurement. The level of accuracy of circular division depends only on the precision of the equipment and the techniques used.

2. According to caliper principle, complete circular division of a circle must be equal to which angle?
a) 120
b) 180
c) 90
d) 360

Explanation: There are some angles which are not an exact fractional circle division, but is considered as a combination of angles which are uniform divisions. By caliper principle complete circular division of a circle must be equal to 360°.

3. How many microscopes are required to marking a circular disc into 90o divisions?
a) 1
b) 2
c) 3
d) 4

Explanation: If the caliper principle is applied for marking a circular disc into 90 degree divisions. Then, in this method, we require the use of two microscopes for taking readings at two different positions simultaneously.

4. How many trial lines are marked firstly when caliper principle is used to mark a circular disc into 90o divisions?
a) 5
b) 4
c) 3
d) 2

Explanation: Firstly two trial lines namely ‘1’ and ‘2’ are marked approximately at 180 degree and the two microscopes A and B are set against these marks. This practice is to divide a circle into two equal halves.

5. How many marks are needed to mark a circular table into 180o divisions using caliper principle?
a) 1
b) 2
c) 3
d) 4

Explanation: 2 lines are marked at approx. 180° and individual microscopes set against these marks, let microscope A for mark 1 & B for 2. The position below B is noted & marked as 3. If the line division of 1 & 2 was exactly 180°, then the difference between 1 and 3 is the twice the error from 180° which can be measured. The space between 1 and 3 is divided by 4. Then 2 and 4 divide the circle into 180° divisions.

6. Which of the following statement is true for the circular division by caliper principle?
Statement 1: An arbitrary standard of angle is required.
Statement 2: All angles are obtained by the uniform division of the dividing circle.
a) F, T
b) T, T
c) T, F
d) F, F

Explanation: The main advantage of circular division and angular measurements is that, there is no need of arbitrary standard of angle but all angles can be obtained by uniform division of the circle.

7. How many marks are needed to mark a circular table into 90o divisions?
a) 2
b) 4
c) 6
d) 8

Explanation: Eight marks are required to divide a circular table into 90 degree division. Four marks are required to divide it correctly 180 degree say 0 to 180 and then another four marks are needed to divide it in 90 to 270 degree. By this table is divided into 90 degree divisions.

8. Which of the following option is true for caliper principle?
Statement 1: This principle can be used to calibrate precision polygons.
Statement 2: Fully calibrated lines can be correctly engraved after marking the circular table and also after calibration of lines.
a) T, F
b) F, F
c) T, T
d) F, T

Explanation: Caliper principle can also be used to calibrate the polygons. After dividing the circles, lines can be correctly engraved on the disc at given intervals. By using the calibration of lines and it’s known for errors of setting.

Sanfoundry Global Education & Learning Series – Engineering Metrology.