Hall Ticket No Question Paper Code: BCC201
INSTITUTE OF AERONAUTICAL ENGINEERING
(Autonomous)
M.Tech I Semester End Examinations (Regular) January, 2018
Regulation: IARE-R16
PRECISION ENGINEERING
(CAD/CAM)
Time: 3 Hours Max Marks: 70
Answer ONE Question from each Unit
All Questions Carry Equal Marks
All parts of the question must be answered in one place only
UNIT I
1. What are the main factors relevant to the accuracy of N.C machining.
Describe about errors due to numerical interpolation
2. Explain about errors due to velocity lags.
Define
i. Datum features
ii. Datum features of size
iii. Datums
UNIT II
3. Explain about function, geometric analysis and location accuracy of grouped datum systems.

Discuss about three-plane datum system.
4. Explain about primary, secondary and tertiary datum planes.
Explain geometric analysis and write its applications.
UNIT III
5. Explain
i. Mean
ii. Variance
iii. Skewness
iv. Feature tolerance
Discuss the relation between tolerance grades and machining process.
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6. In the measurement of surface roughness heights of 20 successive peaks and valleys measured
from a datum are as follows
45,25,40,25,35,16,40,22,25,34,25,40,20,36,28,18,20,25,30,38
If these measurements were made over a length of 20 mm, determine the C.L.A and R.M.S values
of the surface.
What is meant by geometrical tolerance? And specify any three characteristics and its tolerance
symbols of single features.
UNIT IV
7. What is the information given in a tolerance chart?
Discuss about tolerance chart.
8. In a hole and shaft assembly of 30 mm nominal size, the tolerance for hole and shaft are specified
below.
Hole: 30+0:02
+0:00mm

Determine
i. Hole tolerance and shaft tolerance
ii. Maximum metal limit or condition for hole and shaft
iii. Allowance
iv. Type of fit
What is meant by datum feature? How single and two datum features are indicated on drawing?

UNIT V
9. Describe with help of neat sketches the principle and construction of an auto-collimator.
Explain in process measurement of position of processing on machine measurement of dimensional
feature.
10. What is meant by an optical measuring system? Explain.
With the help of neat sketch explain the construction and working principle of a profile projector.

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