Deck 2: Geometric Modeling

Question 1

For generating Coons patch we require

A)A set of grid points on surface
B)A set of control points
C)Four bounding curves defining surface
D)Two bounding curves and a set of grid control points

Answer 1

Four bounding curves defining surface

Question 2

In a 2-D CAD package, clockwise circular arc of radius, 5, specified from P1 (15,10) to P2 (10,15)will have its center at

A)(10, 10)
B)(15, 10)
C)(15, 15)
D)(10, 15)

Answer 2

(10, 10)

Question 3

In the following geometric modelling techniques which are not three-dimensional modelling?

A)Wireframe modelling
B)Drafting
C)Surface modelling
D)solid modelling

Answer 3

Drafting

Question 4

In the following three-dimensional modelling techniques. Which do not require much computer time and memory?

A)Surface modelling
B)Solid modelling
C)Wireframe modelling
D)All of the above

Question 5

In the following geometric modelling techniques. which cannot be used for finite element analysis:

A)Wireframe modelling
B)Surface modelling
C)Solid modeling
D)none of the above

Question 6

In the following geometric primitives. which is not a solid entity of CSG modelling:

A)Box
B)Cone
C)Cylinder
D)Circle

Question 7

Which of the following is not an analytical entity?

A)Line
B)Circle
C)Spline
D)Parabola

Question 8

Which of the following is not a synthetic entity?

A)Hyperbola
B)Bezier curve
C)B-spline curve
D)Cubic spline curve

Question 9

Which one of the following does not belong to the family of conics?

A)Parabola
B)Ellipse
C)Hyperbola
D)Line

Question 10

The number of tangents required to describe cubic splines is

A)2
B)1
C)3
D)4

Question 11

The shape of Bezier curve is controlled by

A)Control points
B)Knots
C)End points
D)All the above

Question 12

The curve that follows a convex hull property is:

A)Cubic spline
B)B-spline
C)Bezier curve
D)Both (b) and (c)

Question 13

The degree of the Bezier curve with n control points is

A)n + 1
B)n - 1
C)n
D)2n

Question 14

The degree of the B-spline with varying knot vectors

A)Increases with knot vectors
B)Decreases with knot vectors
C)Remains constant
D)none of the above

Question 15

The number of non-coincidental points required to define the simplest surface are

A)4
B)3
C)2
D)5

Question 16

The tensor product technique constraints surfaces by two curves.

A)2
B)1
C)3
D)4

Question 17

In the bezier curve, the curve is always to first and last segments of the polygon

A)normal
B)parallel
C)tangent
D)none of the above

Question 18

The unit vector in the direction of the line is defined as .

A)tangent vector+length of the line
B)tangent vector-length of the line
C)tangent vector/length of the line
D)length of the line/tangent vector

Question 19

From the following, which is an axisymmetric surface?

A)Plane Surface
B)Ruled Surface
C)Surface of Revolution
D)All of the above

Question 20

curves allow local control of the curve

A)Analytical
B)Hermite cubic spline
C)Beizer
D)B-Spline

Question 21

To determine the coefficients of the equation - two end-points and the two tangent vectors. This statement is true for which of the following

A)B-spline curve
B)Hermite Cubic Spline Curve
C)Beizer curve
D)none of the above

Question 22

In synthetic curves, second-order continuity yields

A)a position continuous curve
B)a slope continuous curve
C)a curvature continuous curve
D)none of the above

Question 23

Mathematically, the ellipse is a curve generated by a point moving in space such that at any position the sum of its distances from two fixed points (foci) is constant and equal to

A)the major diameter
B)the minor diameter
C)semi major diameter
D)semi-minor diameter

Question 24

When a smooth curve is approximated through the data points, then the curve is known as

A)interpolant curve
B)approximation curve
C)pitch curve
D)data curve

Question 25

In Beizer Curve, the curve follows

A)the control points
B)the shape of the defining polygon
C)the defining points
D)none of the above

Question 26

In Beizer Curve, the flexibility of the shape would increase with

A)decrease in the number of vertices
B)increase in the number of vertices
C)decrease in control points
D)none of the above

Question 27

The number of control points can be added or subtracted in .

A)Bezier curve
B)B-spline curve
C)Cubic spline curve
D)all of the above

Question 28

The degree of the curve is independent of the number of control points in .

A)Hermite cubic spline curve
B)Bezier curve
C)B-spline curve
D)Hyperbola

Question 29

The is used to create a surface using curves that form closed boundaries.

A)ruled Surface
B)plane Surface
C)coons patch
D)surface of Revolution

Question 30

B-rep and C-Rep are the methods of

A)solid modeling
B)surface modeling
C)wireframe modeling
D)2D modeling

Question 31

Which kind of model can store information about geometry

A)Solid model
B)Surface model
C)Wireframe model
D)none of the above

Question 32

From the following, which method is also called as the Building Block Approach?

A)Cellular Decomposition
B)Spatial Occupancy Enumeration
C)Generalized Sweeps
D)Constructive Solid Geometry

Question 33

Structuring and combining the primitives of the solid model in the graphics database, is achieved by the use of…..

A)FEA
B)transformations
C)boolean operations
D)none of the above

Question 34

The data representation of CSG objects is represented by

A)a binary tree
B)a boolean operation
C)a primitive
D)none of the above

Question 35

is an extension of the wireframe model with additional face information added.

A)CSG
B)B-rep
C)Loft
D)none of the above

Question 36

For 3D modeling of automobile body styling, which of the following is a preferred technique?

A)Constructive Solid Geometry
B)Pure Primitive Instancing
C)Boundary Representation
D)Spatial Occupancy Enumeration

Question 37

Which of the following uses a number of two-dimensional profiles for generating a three-dimensional object?

A)Tweaking
B)Lofting
C)Filleting
D)none of the above

Question 38

To create a hollow part, which of the following command would be most efficient?

A)Extrude
B)Sweep
C)Shell
D)Revolve

Question 39

The curve is defined as the locus of a point moving with _ degree of freedom

A)0
B)1
C)2
D)3

Question 40

Write parametric equation of line having end points P1(3,5,8) and P2 (6,4,3).

A)[3 5 8]+u[3 -1 -5]
B)[3 5 8]+u[3 1 5]
C)[3 8 5]+u[3 -1 -5]
D)[3 5 8]+u[-3 1 5]

Question 41

Find the tangent vector of line having end points P1(3,5,8) and P2 (6,4,3)

A)3i+j-5k
B)3i-j-5k
C)3i-j+5k
D)-3i-j-5k

Question 42

Find coordinates of points on line having end points P1(3,5,8) and P2 (6,4,3) at u=0.25

A)[3.75 4.25 6.25]
B)[3.25 4.25 6.25]
C)[3.75 4.75 6.75]
D)[4.25 3.75 6.25]

Question 43

Two lines are parallel when

A)P1 X P2=0
B)P1 . P2=0
C)P1 = P2
D)P1+ P2=0

Question 44

Two lines L1 and L2 having Parametric equations are P1=[3 4 7]+u[2 2 -6] and P2=[1 5 -2]+u[1 4 2]. Tangent vector for line L1

A)2i+2j-6k
B)2i+2j+6k
C)2i-2j-6k
D)6-2j-2k

Question 45

These questions are intricately interconnected, as the answer to the first question lays the foundation for comprehending and addressing the second question effectively.

-Tangent vector for line L2

A)i+4j-k
B)2i+4j+k
C)i-4j-2k
D)i+4j+2k

Question 46

These questions are intricately interconnected, as the answer to the first question lays the foundation for comprehending and addressing the second question effectively.

-Lines are perpendicular?

Question 47

Parametric equation for circle

A)X=x+Rcosu; Y=y+Rsinu; Z=z
B)X=Rcosu; Y=Rsinu; Z=z
C)X=x+Rsinu; Y=y+Rcosu; Z=z
D)X=Rsinu; Y=y+Rcosu; Z=z

Question 48

Center point of circle

A)[x1+x2]/2; [y1+y2]/2; [z1+z2]/2
B)[x1-x2]/2; [y1-y2]/2; [z1-z2]/2
C)[x1-x2]; [y1-y2]; [z1-z2]
D)[x2-x1]; [y2-y1]; [z2-z1]

Question 49

A circle is represented by center point [5,5] and radius 6 units. Find the parametric equation of circle and determine the various points on circle in first quadrant if increment in angle by 45o

A)9.24,9.24
B)9.42,9.42
C)9,9
D)11,5

Question 50

A circle is passing through two end points A[6,4] and B[10,10]. Find center point of circle

A)7,8
B)8,8
C)8,7
D)7,7

Question 51

These questions are intricately interconnected, as the answer to the first question lays the foundation for comprehending and addressing the second question effectively.

-find radius of circle

A)3
B)3.6
C)4
D)3.5

Question 52

These questions are intricately interconnected, as the answer to the first question lays the foundation for comprehending and addressing the second question effectively.

-find coordinates of point on circle at u=0

A)11.6, 7
B)7, 11
C)11, 7
D)11.5, 7.5

Question 53

Find parametric equation for X-coordinates of hermite cubic spline curve having end points P0[4,4]; P1[8,5]

A)-5u3+8u2+u+1
B)5u3+8u2+u+1
C)8u3-5u2-u+1
D)8u3+5u2+u+1

Question 54

Find parametric equation for Y-coordinates of Hermite cubic spline curve having end points P0[4,4]; P1[8,5]

A)2u3-3u2+2u+4
B)3u3-2u2-2u-4
C)2u3-3u2-2u-4
D)2u3+3u2+2u+4

Question 55

C0 continuity refers to

A)Common tangent
B)Common curvature
C)Common point
D)Common normal

Question 56

C' continuity refers to

A)Common tangent
B)Common curvature
C)Common point
D)Common normal

Question 57

C" continuity refers to

A)Common tangent
B)Common curvature
C)Common point
D)Common normal

Question 58

Which of the following is not a method to describe a curve mathematically?

A)Explicit form
B)Laplace form
C)Implicit form
D)Parametric form

Question 59

When the curve passes through all the data points, then the curve is known as

A)approximation curve
B)pitch curve
C)data curve
D)interpolant curve

Question 60

When a smooth curve is approximated through the data points, then the curve is known as

A)approximation curve
B)pitch curve
C)data curve
D)interpolant curve

Question 61

Synthetic curve pass through defined data points and thus can be represented by

A)polynomial equations
B)exponential equations
C)partial differential equations
D)differential equations

Question 62

Mathematically, the ellipse is a curve generated by a point moving in space such that at any position the sum of its distances from two fixed points (foci) is constant and equal to

A)the major diameter
B)the minor diameter
C)semi major diameter
D)semi-minor diameter

Question 63

The parabola is defined mathematically as a curve generated by a point that moves such that its distance from the focus is always__________the distance to the directrix

A)larger than
B)smaller than
C)equal to
D)none of the above

Question 64

In synthetic curves, zero-order continuity yields

A)a position continuous curve
B)a slope continuous curve
C)a curvature continuous curve
D)none of the above

Question 65

In synthetic curves, first-order continuity yields

A)a position continuous curve
B)a slope continuous curve
C)a curvature continuous curve
D)none of the above

Question 66

The B-spline curve has a

A)first-order continuity
B)second-order continuity
C)zero-order continuity
D)none of the above

Question 67

To determine the coefficients of the equation - two end-points and the two tangent vectors. This statement is true for which of the following?

A)B-spline curve
B)Hermite Cubic Spline Curve
C)Beizer curve
D)none of the above

Question 68

The Bezier curve is smoother than the Hermite cubic spline because it has _________ order derivatives.

A)lower
B)higher
C)lower and higher both
D)none of the above

Question 69

In the bezier curve, the curve is always________to first and last segments of the polygon

A)normal
B)parallel
C)tangent
D)none of the above

Question 70

________curves allow local control of the curve.

A)Analytical
B)Hermite cubic spline
C)Beizer
D)B-Spline

Question 71

In Beizer Curve, the curve follows __________

A)the control points
B)the shape of the defining polygon
C)the defining points
D)none of the above

Question 72

In Beizer Curve, the flexibility of the shape would increase with _______ of the polygon.

A)decrease in the number of vertices
B)increase in the number of vertices
C)decrease in control points
D)none of the above

Question 73

The degree of the curve is independent of the number of control points in _____

A)Hermite cubic spline curve
B)Bezier curve
C)B-spline curve
D)Hyperbola

Question 74

In modeling of a tabulated cylinder, the plane of the curve is _______

A)along the curve
B)normal to the curve
C)along the axis of the cylinder
D)perpendicular to the axis of the cylinder

Question 75

The ___________ is used to create a surface using curves that form closed boundaries

A)ruled Surface
B)plane Surface
C)coons patch
D)surface of Revolution

Question 76

________ command gives an array of object in 3D modeling

A)Extrude
B)Revolve
C)Pattern
D)All of the above

Question 77

To create a hollow part, which of the following command would be most efficient

A)Extrude
B)Sweep
C)Shell
D)Revolve

Question 78

A cylinder can be created by drawing a rectangular shape using the ________ tool.

A)revolve
B)sweep
C)extrude
D)all of the above

Question 79

For 3D modeling of automobile body styling, which of the following is a preferred technique

A)Constructive Solid Geometry
B)Pure Primitive Instancing
C)Boundary Representation
D)Spatial Occupancy Enumeration