Subject : Computer Graphics (MC0072)

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PART A

Q.1 Consider the line from (0, 0) to (5,5).

Rasterizing the line with the Bresenham’s

algorithm yields error term =

A) -1/2

B) 1/2

C) 4/5

D) 1/5

Q.2 As the mouse is rolled around on a flat

surface, its movement is in ____ direction is

translated into rotation of the wheel

A) Orthogonal

B) Oblique

C) Parallel

D) None of these

Q.3 Representing a three dimensional object in

a two dimensional medium is called

A) Projection

B) Transformation

C) Translation

D) Rotation

Q.4 Process of determining which pixels will

provide the best approximation to the desired

line is properly known as _____

A) Scan conversion

B) rasterization

C) Interlacing

D) All of the above

Q.5 The glow off by the, phosphor during

exposure to the electron beam is known as

A) Persistence

B) Phosphorescence

C) Fluorescence

D) All of the above

Q.6 Disadvantage of edge fill algorithm is

A) Expense associated with sorting the various lists

B) Expense associated with maintaining

C) Algorithm is limited to input/output considerations

D) All of the above

Q.7 Bresenham’s circle algorithm uses ____ of a

circle to generate a circle

A) 2-way-symmetry

B) 8-way-symmetry

C) 4-way-symmetry

D) 6-way-symmetry

Q.8 In ordered, edge list algorithm, each pixel

in the display is visited ______

A) twice

B) only once

C) thrice

D) cannot be specified

Q.9 “The mouse cannot be used for tracing

paper―. This statement is

A) FALSE

B) TRUE

C) Partially true

D) Can’t predictable

Q.10 In Algorithm for identifying completely

visible and most invisible line the number of

regions use is

A) 8

B) 4

C) 9

D) 16

Q.11 A object-space algorithm for hidden surface

removal work concentrates on _____

A) geometrical relationships among the objects in the scene

B) Final image

C) Both A) and B)

D) Spatial relationship of final object

Q.12 Which of the following line is partially

visible?

A) Line ab with end point codes 0100 and 0100

B) Line bc with end point codes 1000 and 0010

C) Line Pq with endpoint codes 1001 and 1000

D) line xy with end point codes 0000 and 0010

Q.13 After identifying visible surfaces by a hidden

surface algorithm, is ______ is used to

compute the intensities and colors to display for

the surface

A) Shading model

B) Perspective Projection

C) Scaling

D) Mirror reflection

Q.14 If the slope of the line is zero, the line is

A) parallel to left and right edges

B) perpendicular to top and bottom edges

C) perpendicular to left and right edges

D) only top edges need to be checked for intersections

Q.15 _____ is the process of extracting a

portion of a database

A) Flipping

B) Clipping

C) Concatenation

D) Spooling

Q.16 ______ statement is false

A) Farther an object is from the center of projection, the smaller it appears

B) Projections of lines that are parallel to the view plane appear to meet at some

point on the view plane.

C) Objects behind the center of projection are projected upside down and backward

on to the view plane

D) A finite line segment joining a point which lies back of viewer point in back of

the viewer, is actually projected to a broken line of infinite extent

Q.17 When phosphor will no longer be

fluoroscent, it is said to be

A) dead

B) Burned

C) Inactive

D) all of the above

Q.18 The error term for a non zero intercept of

General Bresenham’s Algorithm is

A) 2dy-dx

B) 2dx-dy

C) 2dx+dy

D) 2dy+dx

Q.19 The error term of integer Bresenham’s

Algorithm is given as

A) 2edy

B) -2dex

C) 2edxdy

D) 2edx

Q.20 If 4 bit binary representation of ‘6’ is shifted

right 4time them it yields

A) 4

B) 12

C) 3

D) 16

Q.21 _____ algorithms are not limited to simple

polygons

A) Edge fill algorithm

B) Edge flag algorithm

C) Fence fill algorithm

D) all of the above

Q.22 Integer (-8.5) =

A) -8

B) -9

C) -10

D) None of these

Q.23 Find the slope of line from

P1 (-3/2, -1) to P2 (3/2, 2)

A) 2/3

B) 1/3

C) ½

D) 1

Q.24 For the line from Pl(-3/2, 1/6) to P2(1/2,

3/2), the slope is ______

A) 2/3

B) 3/2

C) 1/6

D) 1/3

Q.25 The equation of the infinite line through

P1(X1 Y1) and P2(X2, Y2) is Y =

A) m(x-x1)+y1

B) m(y-y1)+x1

C) m(x1-x)+y1

D) m(y1-y)+XL

Q.26 S-1sxsy =

A) Ssysx

B) S1/sx 1/sy

C) -Ssxsy

D) None of these

Q.27 1. If the refresh rate is greater than the

phosphor’s persistence, moving object will tend

to become

A) Blurred

B) Brightened

C) Flickered

D) None of these

Q.28 Refreshing of a CRT is done to avoid

A) Flickering

B) Interlacing

C) Blurring

D) None of the above

Q.29 A scaling constant indicates an expansion of

length

A) Equal to 1

B) greater than one

C) less than 1

D) less than 0

Q.30 The process of determining which pixel will

provided the best approximation to the desired

line is know as

A) Scan conversion

B) lipping

C) rasterization

D) None of these

Q.31 Choose the oblique projections from

below

A) General

B) Cavalier

C) Cabinet

D) All the above

Q.32 _____ algorithm can be used to handle on

cave polygons

A) Weiler algorithm

B) Atherton algorithm

C) Weiler and Atherton algorithm

D) None of the above

Q.33 Sutherland-Hodgman algorithm is used for

A) line drawing

B) Polygon clipping

C) Circle generating

D) None of these

Q.34 Disadvantage of using mouse is

A) Cannot be used for tracing data from paper

B) Very difficult to handprint characters recognition by the computer

C) Both A) and B)

D) None of the above

Q.35 In a conventional CRT the yoke is connected

to a ___

A) Sweep

B) Scan generator

C) Either A) or B)

D) None of these

Q.36 Select the feature of Midpoint subdivision

algorithm

A) Requires calculation of the intersection of the line with window page

B) Hardware implementation of the algorithm is slow

C) Software implementation of the algorithm is slow

D) None of the above

Q.37 In modified scan line co-ordinate system,

horizontal edges are ignored, because

A) Horizontal edges intersect a scan line

B) Horizontal edges are not formed

C) Horizontal edges are always formed

D) Horizontal edges cannot intersect a scan line

Q.38 The process of scaling changes ___of an

object

A) Sign

B) Dimension

C) Both A) and B)

D) None of these

PART B

Q.1 The glow given off by the, phosphor

during exposure to the electron beam is know

as _____ and the continuing glow given off

after the beam is removed is known as _____

A) Persistence, fluorescence

B) Phosphorescence, fluorescence

C) Fluorescence, phosphorescence

D) Persistence, phosphorescence

Q.2 Except at boundary edges, adjacent pixels

are likely to have the same characteristics, and

this property is referred as ______ and far a

raster scan graphics device adjacent pixels on a

scan line are likely to have the same

characteris

A) Scan line, Boundary

B) Boundary, Spatial

C) Spatial, Scan line

D) Scan line, Spatial

Q.3 In a CRT, at the end of each line the beam

must turned off and redirected back to the left

hand side of the CRT. The return sweep is

called _____ and shutting off of the electron

beam as it returns from the bottom of the

display at the

A) Retracing, Blanking

B) Blanldng, retracing

C) horizontal retrace blanking, vertical retrace blanking

D) vertical retrace blanking, horizontal retrace blanking

Q.4 Perspective drawing are characterized by

____ and _____

A) Vanishing Points, view confusion

B) View confusion, Perspective foreshortening

C) Perspective foreshortening, vanishing points

D) Topological distortion, view confusion

Q.5 Select true statements regarding Edge Flag

Algorithm

i) It is three step process

ii) The second step is to fill between bounding

pixels

iii) The first step is to outline the contour

A) i) and ii)

B) ii) and iii)

C) i) and iii)

D) i), ii) and iii)

Q.6 ____is the place where displays image is

stored as a matrix of intensity values and

_____ passes the contents of the frame buffer

to the monitor

A) Digital memory, Displays controller

B) Television monitor, Displays controller

C) Digital memory, Television monitor

D) None of the above

Q.7 Midpoint of the line having the end points (-

308, 632) and (820, -136) is

A) (247, 256)

B) (257,243)

C) (256, 248)

D) (0,0)

Q.8 Choose the ingredients of the shading

models

i) Properties of intensities

ii) Properties of the surface

iii) Properties of the illumination falling on it

A) i) and iii)

B) ii) and iii)

C) i) and ii)

D) i), ii) and iii)

Q.9 Consider the line from (0, 0) to (5, 5) then

applying Bresenham’s Algorithm yields dy =

______ and e = _______

A) 5, ½

B) -5, -½

C) 5, -½

D) -5, ½

Q.10 In Cohen Sutherland algorithm ___ bit is

set if the end point is to the right of the window

and ______ bit is set if the end point is below

the window

A) First, Third

B) Second, Third

C) First, Fourth

D) Fourth, Second

Q.11 _____ gives the correct definition of Edge

fill algorithm

A) For each scan line intersecting a polygon edge at (x complement all pixels whose

midpoints lie to the right of(x

B) For each scan line intersecting a polygon edge at (x complement all pixels whose

midpoints lie to the left of (xi.yi).

C) If the intersection is to the left of the fence, complement all pixels whose

midpoint lies to left or on the intersection of the scan line

D) If the intersection is to the right of the fence, complement all the pixels

Q.12 Match the following intersections with the

window edges

Set – A

i) y=m(XL-X1)+y1 mK±M

ii) y=X1+(y=X1+(1/m) (yB-y1) mK0

Set – B

1. Right

2. Top

3. Left

4. Bottom

A) i) -4, ii) -3

B) i) -3, ii) -4

C) i) -2, ii) -1

D) i) -4, ii) -1

Q.13 Choose the oblique projectors from below

i) General

ii) Auxiliary views

iii) Trimetric

iv) One principal vanishing point

v) Cabinet

A) i), iii) and iv)

B) i), iii) and v)

C) i), ii) and iv)

D) i) and v)

Q.14 Find the slop and mid point of the line

P1(-3/2, 1/6) to P2 (1/2, 3/2)

A) -2/3, (1/2, 5/3)

B) -3/2, (1/2, -5/3)

C) -1/2, (1/2 -5/3)

D) 2/3, (-1/2, 5/3)

Q.15 Which of the following specifies the process

of scan converting a circle using Bresenham’s

algorithm

A) If the eight-way symmetry of a circle is used to generate a circle, points will

have to be 90° to 450 angle

B) If the eight-way symmetry of a circle is used to generate a circle, moves will be

made only in the positive direction

C) If the eight-way symmetry of a circle is used to generate a circle, points will only

have to be generated through a 90° angle

D) If the weight-way symmetry of a circle is used to be generated a circle, points

will only have to be generated through a 450 angle and if points are generated

from 900 to 450 moves will be made only in the +x and —y directions

PART C

Q.1 Select the features applicable for seed fill

algorithms

a. Algorithm attempts to find and fill all pixels

interior to the region

b. If the region is interior-defined, then all the

pixels in the interior of the region boundary

have

A) a, b, c, d, e

B) c, d, e

C) b, d

D) a, c, d, e

Q.2 In two dimensional clipping, if any

coordinate of either end point is outside the

window, then the line is _____ . If both end

points are left, right above or below the

window, the line is _____. If both end points

are interior to the

A) Trivially invisible, not totally visible, totally visible

B) Not tolally visible, trivially invisible, visible

C) Totally visible, trivially invisible, not totally visible

D) Visible, Not totally visible, trivially invisible

Q.3 Match the following:-

Set – A

i) Used to create a clear picture

ii) Used to control the direction of the electron

beam

iii) Used to regulate the flow of electrons

Set – B

1. Deflection yoke

2. Electron gun

3. Focusing e

A) i)-2, ii)-3, iii)-4

B) i)-3, ii)-4, iii)-2

C) i)-2, ii)-4, iii)-1

D) i)-3, ii)-1, iii)-4

Q.4 Consider the DDA algorithm. Consider the

line from (0, 0) to (-8, -4) in the third quadrant

then value of length = _______, dx = ______

and dy = ______

A) -4, 1, -0.5

B) .4, 1, 0.5

C) -8, -1, 0.5

D) 8, -1, -0.5

Q.5 Bresenham’s line algorithm includes _____

features

a. Algorithm seeks to select the optimum raster

locations to represent a straight line

b. If the error term is negative, the line will

pass below the middle of the pixel

c. Algorit

A) a, b, c, d

B) a, d, e

C) only b and d

D) a, b, c, e

Q.6 Select true statements regarding edge fill

algorithm

i) This algorithm is most conveniently used with

frame buffer

ii) This algorithm is limited by input/output

considerations

iii) This algorithm allows the polygon edges to

be

A) ii), iii) and iv)

B) i), ii) and iii)

C) i) and ii)

D) All the above

Q.7 Which of the following statements are false

regarding polygon dipping algorithm?

a. It is based on the observation that it is

relatively easy to dip a polygon against a single

clipping edge

b. Algorithm operates vertices of the polygo

A) c, d, e

B) a, b

C) a, d, e

D) b, d, e

Q.8 Match the following:-

Set A

i) Projection plane parallel to principal planes

ii) Projection not perpendicular to projection

plane

iii) Projection plane not parallel to principal

plane

Set B

1. Orthographic

2. Axonometri

A) i)-3, ii)-4, iii)-2

B) i)-4, ii)-1, iii)-3

C) i)-3, ii)-4, iii)-1

D) i)-2, ii)-4, iii)-1

Q.9 Select the points true for two dimensions

graphics transformation

a. If the displacement of a object p(x, y) is

given by the vector V=t + t. , then new object

co-ordinates are x+t and y+ty

b. In a scaling transformation, only origin <b

A) a, b, c, d, e

B) a, b, c, d

C) c, e

D) b, d, e

Q.10 State True or False for raster-scan CRT

a. An electron gun consists of a heater and a

cathode

b. Control electrode is used to regulate the flow

of electrons

c. Focusing electrode is used to control the

direction of electron beam <b

A) a-T, b-T, c-F, d-F, e-F

B) a-I, b-F, c-T, d-T, e-F

C) a-F, b-I, c-F, d-F, e-T

D) a-I, b-F, c-F, d-I, e-T

Q.11 Consider the line (0, 0) to 5, 5)

Rasterizing the line with the Bresenham’s

algorithms

yields initial calculations dx = ______dy = ____

and e = ____

A) 5. 0 -0.5

B) 5, 5, 0.5

C) 5, 5 -0.5

D) -0, 5, 0.5

Q.12 ______ gives the correct representation of

simple incremental algorithm

A) position = start step = increment 1. If position end end then 2 if position

B) position = start step = increment 1. If position _ end end then 3 if position

C) position = start step = increment 1. If position_ end end then 2 if position

D) position = start step = increment 1. position=position_step go to 1 2. If

position_end end then 3 if position

Q.13 Match the following:

Set – A

i) The farther an object is from the center of

projection, the smaller it appears

ii) Object behind the center of projection are

projected upside down

iii) A finite line segment joining a point which <b

A) i)-3, ii)-4, iii)-2

B) i)-4, ii)-1, iii)-2

C) i)-2, ii)-3, iii)-4

D) i)-3, ii)-1, iii)-4

Q.14 Consider the edge flag algorithm

Contour outline:

for x+1/2>x intersection to the boundary value

Fill:

For each scan line intersecting the polygon

Inside = _______

for X = 0 (left) to X=Xmax(right)

if the pixel at x is set to t

A) True, false, set, reset

B) False, true, reset, set

C) False, True, set, reset

D) True, false, set, set