Q1 – Consider a triangle PQR with coordinates as P(0, 0), Q(2, 2) and R(10, 4). If this triangle is to be magnified to four times its size while keeping R(10, 4) fixed, then the coordinates of the magnified triangle are
(-20, -12), Q(-20, -4) and R(10, 4)
(-30, -12), Q(-22, -4) and R(10, 4)
(-25, -10), Q(22, -4) and R(10, 4)
(30, -12), Q(-22, 4) and R(10, 4)
(UGC NET DEC 2023)
Ans – (2)
Explanation – In this question, we will use vectors to simplify the points.
Vector P = (0, 0)
Vector Q = (2, 2)
Vector R = (10, 4) and after magnification vector R is unchanged.
Vector R is fixed and vector P and Q are magnified by 4 times.
So, vector P – vector R = (0, 0) – (10, 4) = (-10, -4)
And, vector Q – vector R = (2, 2) – (10, 4) = (-8, -2)
By applying magnification of 4 times, we have got
Vector P – Vector R = 4*(-10, -4) = (-40, -16)
Vector P = (-40, -16) + Vector R
Vector P = (-40, -16) + (10, 4) = (-30, -12)
Also, Vector Q – Vector R = 4*(-8, -2) = (-32, -8)
Vector Q = (-32, -8) + Vector R
Vector Q = (-32, -8) + (10, 4) = (-22, -4)
Q2 – The Hue of a colour is related to its:
Luminance
Saturation
Incandescence
Wavelength
(UGC NET DEC 2023)
Ans – (4)
Explanation – Hue or the Color temperature is a property of light having to do with a change in color due to a change in a wavelength. Hue is the color perceived. It is the dominant color perceived by the human eye, such as red, blue, or green, and depends on the wavelength of light.
Luminance refers to color brightness.
Saturation refers to the purity level of a color.
Incandescence is light given off because of high temperature.
Q3 – Match List-1 with List-2
List – 1 | List – 2 |
(a) Bresenham | I. Hidden surface removal |
(b) Cohen – Sutherland | II. Line drawing algorithm |
(c) Sutherland – Hodgeman | III. Line clipping algorithm |
(d) Z-buffer | IV. Polygon clipping algorithm |
Choose the correct answer from the options given below
(a) | (b) | (c) | (d) | |
1. | III | II | IV | I |
2. | II | III | I | IV |
3. | II | III | IV | I |
4. | II | IV | III | I |
(UGC NET DEC 2023)
Ans – (3)
Explanation – (a) Bresenham’s Algorithm → (II) Line Drawing Algorithm
This is a technique for quickly rasterizing lines that fits the needs of integer calculations.
(b) Cohen-Sutherland Algorithm → (III) Line Clipping Algorithm
This is the technique for clipping lines that lie partially or completely outside a given rectangular boundary.
(c) Sutherland-Hodgeman Algorithm → (IV) Polygon Clipping Algorithm
A method to clip polygons against a rectangular clipping window.
(d) Z-buffer Algorithm → (I) Hidden Surface Removal
Used in 3D graphics to determine which surfaces are visible and which are hidden.
Q4 – Consider the three points P1(1, 2, 0), P2(3, 6, 20) and P3(2, 4, 6) and a view point C(0, 0, -10).
Choose the correct options.
(a) P1 obscure P2, if viewed from C.
(b) P2 obscure P1, if viewed from C.
(c) P3 does not obscure P1, if viewed from C.
(d) P2 does not obscure P3, if viewed from C.
Choose the correct answer from the options given below:
(a), (b) and (c) only
(a), (c) and (d) only
(b), (c) and (d) only
(a), (b) and (d) only
(UGC NET DEC 2023)
Ans – (2)
Explanation – Obscure means to block the view or to hide anything from the sight.
Points (x, y) of C, P1, P3 and P2 is (0, 0), (1, 2), (2, 4) and (3, 6) respectively. Means y is just double the x, so in that graph C is the first point, then second point is P1, then third point is P3, and then P2 is the last one.
The z point of C, P1, P3 and P2 is -10, 0, 6 and 20.
(a) P1 obscure P2, if viewed from C. – Correct (C -> P1 -> P2)
(b) P2 obscure P1, if viewed from C. – Incorrect (C -> P1 -> P2)
(c) P3 does not obscure P1, if viewed from C. – Correct (C -> P1 -> P3)
(d) P2 does not obscure P3, if viewed from C. – Correct (C -> P3 -> P3).