JNTU Kakinada B-Tech 3-1 RT31036 I METROLOGY R13 April 2018 Question Paper

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Code No: RT31036
III B. Tech I Semester Supplementary Examinations, May – 2018
METROLOGY (Mechanical Engineering)Time: 3 hours Max. Marks: 70
Note: 1. Question Paper consists of two parts (Part-A and Part-B) 2. Answering the question in Part-A is compulsory
3. Answer any THREE Questions from Part-B
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PART ?A
1 a) What do you understand by fits? [3M]
b) Mention few applications of bevel protractors. [4M]
c) What do you mean by interferometers? [4M]
d) How is Ten-point average of surface roughness calculated? [3M]
e) What do you mean by error in screw threads? [4M]
f) What is purpose of performing alignment test on machine tool? [4M]
PART -B
2 a) Bring out the salient features of British standard and ISO systems of limits and
fits.
[6M]
b) A 50 mm diameter shaft and bearing are to be assembled with a clearance fit. The
tolerance and allowance are as under.
Allowance = 0.035 mm
Tolerance on hole = 0.025 m
Tolerance of shaft = 0.017 mm
Find the limits of size for the hole and shaft if
i) Hole basis system is used ii) Shaft basis system is used
[10M]
3 a) Explain with neat sketches the variants of sine bars and their applications. [8M]
b) Write detailed notes on progressive and positional limit gauges. [8M]
4 a) Explain flatness interferometer with neat sketch and write its applications. [8M]
b) Explain how flatness errors of lapped surfaces are measured with an optical flat. [8M]
5 a) Explain following methods of specifying roughness value:
i) Peak-to-valley height method ii) Centre-line-average method
iii) Root mean square method
[8M]
b) Explain pneumatic comparator and state the advantages and disadvantages. [8M]
6 a) Explain with neat sketches how the gear tooth vernier caliper is used for checking
the chordal thickness of a gear tooth.
[8M]
b) What is best size wire for effective diameter measurement? Derive a relationship
for the best size wire in terms of its effective diameter?
[8M]
7 a) Explain the procedure for checking the straightness of a component using
autocollimator.
[8M]
b) Explain the parallelism of tailstock sleeve of a lathe machine to saddle movement. [8M]
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R13
SET – 1