# Download GTU B.Tech 2020 Summer 6th Sem 2161903 Computer Aided Design Question Paper

Download GTU (Gujarat Technological University Ahmedabad) B.Tech/BE (Bachelor of Technology/ Bachelor of Engineering) 2020 Summer 6th Sem 2161903 Computer Aided Design Previous Question Paper

Seat No.: ________
Enrolment No.___________
GUJARAT TECHNOLOGICAL UNIVERSITY
BE - SEMESTER? VI EXAMINATION ? SUMMER 2020
Subject Code: 2161903 Date:02/11/2020
Subject Name: COMPUTER AIDED DESIGN
Time: 10:30 AM TO 01:00 PM Total Marks: 70
Instructions:
1. Attempt all questions.

2. Make suitable assumptions wherever necessary.

3. Figures to the right indicate full marks.

MARKS
Q.1 (a) Why CAD is widely used in modern manufacturing industries?
03

(b) Determine raster locations of a line joining two points from A(12, 12) to B(4,
04
2) using DDA line drawing algorithm.

(c) Determine generalized parametric form of a line passing through two points
07
using neat sketch. Find Parametric equation of line through points A(3,-6,7)
and B(5,1,-4).
Q.2 (a) Why Bresenham's algorithm is superior to DDA algorithm?
03

(b) Answer the following:
04
(i) Compare Analytic and Synthetic curves
(ii) Why Homogeneous coordinate transformations are used in CAD?

(c) Prove that the transformation matrix for reflection about the line = - is
07
equivalent to clockwise rotation by 45? followed by reflection relative to Y
axis and finally counter clockwise rotation by 45?.

OR

(c) Find concatenated matrix if the operations are performed as per the following
07
sequence:
a) Rotation through 45? counterclockwise.
b) Translation through 5 and -8 units along the X and Y directions.
c) Rotations through 60? clockwise.
Q.3 (a) Discuss any three properties of solid models. (Don't enlist properties only).
03

(b) Explain following surfaces:
04
(i) Revolved surface (ii) Bezier Surface

(c) A Bezier curve is to be constructed using control points P0 (35, 30), P1 (25,
07
0), P2 (15, 25) and P3 (5, 10). The Bezier curve is anchored at P0 and P3. Find
the equation of the Bezier curve and plot the curve for u= 0, 0.2, 0.4, 0.6, 0.8
and 1.

OR

Q.3 (a) Explain Constructive Solid Geometry (CSG) with sketch.
03

(b) Enlist various types of surfaces. Explain ruled surface.
04

(c) Derive equation of a Hermite's cubic spline curve with two end points P0
07
and P1 and their tangent vectors are
0 and 1 .
Q.4 (a) What are the properties of the Stiffness matrix?
03

(b) What is shape function? Draw a sketch for a linear shape function used in
04
FEM.

(c) How many elements to be considered in the problem of figure 1? Determine
07
Global stiffness matrix bar elements used in the system below:
1

Figure1

OR

Q.4 (a) What do you mean by `Discretization'? State precautions required during
03
discretization.

(b) What do you mean by `Iso-Parametric formulation' of problems in FEM.
04

(c) How many elements to be considered in the problem of figure 2? Determine
07
Global stiffness matrix bar elements used in the system below:
Figure 2
Q.5 (a) List applications areas of Finite Element Analysis (FEA).
03

(b) Enlist steps to be followed for solution of Structural problems using FEM.
04

(c) For one dimensional element shown in Figure 3, temperature at node 1 is
07
100? C and at node 2 is 40? C. Evaluate shape function associated with node
1 and node 2. Calculate temperature at point P. Assume linear shape function
Figure 3

OR
Q.5 (a) What are the types of loading acting on the structure? Give suitable
03
examples.
(b) Define total potential energy. State the principle of minimum potential energy.
04
(c) Analyze the two-members truss shown in Figure 4. Assume EA to be
07
constant for all members. The length of each member is 5m. Area A=0.01
m2 and E=210GPa. Compute nodal displacements and reactions forces.
Determine stresses in each member.
Figure 4
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This post was last modified on 04 March 2021