JUNE 2012 - PAPER III

4. What is Granularity ?

(A) The size of database
(B) The size of data item
(C) The size of record
(D) The size of file

Ans:-B

Explanation:- Granularity refers to the size of any data item. It could be a tuple, relation, database,anything. So the option is B.

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5. Suppose that a given application is run on a 64-processor machine and that 70 percent of the application can be parallelized. Then the expected performance improvement using Amdahl’ s law is

(A) 4.22
(B) 3.22
(C) 3.32
(D) 3.52

Ans:-B

Explanation:-
According to Amdahl's law, in case of parallelization,if P is the proportion of the program that can be made parallel, then (1-P) is the proportion that cannot be parallelized. Then the maximum speedup that can be achieved by using N processor is, S(N)=1/(1-P)+P/N where N refers to the no of processors, and P refers to the proportion that can be parallelized.
In the question above, no of processor, N=64
The proportion of the program that can be made parallel, P = 70%=0.7
So, substituting in the formula, we get, 1/(1-0.7)+0.7/64=1/0.3+0.0109375=1.0.310975
=3.215
=3.22
Therefore, the option is B.

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6. If two fuzzy sets A and B are given with membership functions μA(x) = {0.2, 0.4, 0.8, 0.5, 0.1} μB(x) = {0.1, 0.3, 0.6, 0.3, 0.2} Then the value of μ ––– willbe A∩B

(A) {0.9, 0.7, 0.4, 0.8, 0.9}
(B) {0.2, 0.4, 0.8, 0.5, 0.2}
(C) {0.1, 0.3, 0.6, 0.3, 0.1}
(D) {0.7, 0.3, 0.4, 0.2, 0.7}

Ans:-A

Explanation:-
The fuzzy intersection of two fuzzy sets A and B on universe of discourse X: μA∩B(x) = min [μA(x), μB(x)] , where x∈X
But here in the question, they are asking for complement of AintersectionB and so the answer would be 1-min[A(x),B(x)]. The minimum of 0.2 and 0.1 will be 0.1, and 1-0.1 will be 0.9. The second value is min(0.4,0.3)=0.3 and 1-0.3=0.7
The third value is min(0.8,0.6)=0.6 and 1-0.6=0.4
The fourth value is min(0.5,0.3)=0.3 and 1-0.3=0.7
The last value is min(0.1,0.2)=0.1 and 1-0.1=0.9
The only option which has got the values 0.9,0.7,0.4,0.7 and 0.9, although the fourth value is given as 0.8 instead of 0.7 is option A. So the answer is option A.

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JUNE 2012 - PAPER III - COMPUTER GRAPHICS

JUNE 2012 – PAPER III

 

47. The colour of an object is largely determined by its diffuse reflection coefficient. If Kd = (0.8, 0.4, 0), then what shall be the colour of the object, if the light used is blue and magenta ?

(A) White and Red

(B) Red and Blue

(C) Black and White

(D) Black and Red

Ans:- D

Explanation:-

The color of an object is largely determined by its diffuse reflection coefficient(kd). Kd is assigned a value between 0.0 and 1.0.

0.0  – for dull surface that absorbs almost all light

1.0  – for shiny surface that reflects almost all light.

 

You should understand the range of kd and its meaning very clearly. For colored surfaces, there are three kd values, one for red, green and blue.

Let us consider a polygon with diffuse color(1,0,0). It reflects all of the red light it is hit with, and absorbs all of the blue and green(because red has a value 1, and green and blue has a 0).

If this red polygon is hit with a white light it will appear red. If it is hit with a blue light, or a green light, or an aqua light it will appear black(as those lights have no red component). If it is hit with a yellow light or a purple light it will appear red(as the polygon will reflect the red component of the light).

 

The kd value given in the equation is kd=(0.8,0.4,0)

What shall be the color of the object if the light used is blue and magenta?. That is the question.

Let us consider the first color. Blue light falls on the object. But the blue component of kd is 0. It means that color is going to be completely absorbed by the object and it will appear black. So, when blue light falls on the object, the object will appear black.

 

Let us consider the next color. Magenta light falls on the object. Magents is a violet-red or purplish-red color. It is midway between red and blue. Since red has a high kd value, it will get reflected more and so the color of the object will be Red.

 

So, the color of the object will be Black and Red. The correct option is D.

 

 

59. The perspective projection matrix, on the view plane z = d where the centre of projection is the origin (0, 0, 0) shall be

 

(A) 0 0 0 d

0 0 d 0

0 d 0 0

d 0 0 1

 

(B)  d 0 0 0

0 d 0 0

0 0 d 0

0 0 1 0

(C) 0 0 0 d

0 0 d 0

0 d 0 0

1 0 0 0

(D) d 0 0 0

0 d 0 0

0 0 d 0

0 0 0 1

 

Ans:- B

 

Explanation:-

 

A perspective transformation is determined by prescribing a center of projection and a view plane. The view plane is determined by its view reference point R₀ and view plane normal N.

The projection transformation as a matrix

 

Per_N,R0 = d₀ 0 0 0

0 d₀ 0 0

0 0 d₀ 0

n1 n2 n3 0

 

The plance z = d is parallel, to the xy plane. Thus the view plane normal vector N is the same as the normal vector K to the xy plance, that is N=K. Choosing the view reference point as R₀(0,0,d), we can identify the parameters

N(n1,n2,n3) = (0,0,1)

R₀(x0,y0,z0)=(0,0,d)

 

So,

d₀ = n1x0 + n2y0 + n3z0 = d

 

and so the projection matrix is

Per_K,R0 = d 0 0 0

0 d 0 0

0 0 d 0

0 0 1 0

So, the correct answer is option B. The same problem is solved in the Schaum’s outlines, Computer Graphics book(pg. no. 138).

 

 

 

 

 

 

 

 

JUNE 2013 - PAPER III

26. An actor in an animation is a small program invoked _______ per frame to determine the characteristics of some object in the animation.

(A) once

(B) twice

(C) 30 times

(D) 60 times

 

Ans:- A

 

Explanation:-

An actor in an animation is a small program invoked once per frame to determine the characteristics of some object in the animation.

 

27. Bresenham line drawing algorithm is attractive because it uses

(A) Real arithmetic only

(B) Integer arithmetic only

(C) Floating point arithmetic

(D) Real and integer arithmetic

 

Ans:- B

 

Explanation:-

 

Bresenhem’s algorithm offers a significant advantage over the other methods, as it avoids floating-point arithmetic and rounding. It is a classic example of an incremental algorithm that computes the location of each pixel along the line based on information about the previous pixel. It uses only integer values and avoids any multiplications.

 

28. The refresh rate above which a picture stops flickering and fuses into a steady image is called _________.

(A) Crucial fusion frequency

(B) Current frequency fusion

(C) Critical fusion frequency

(D) Critically diffused frequency

 

Ans:- C

Explanation:-

The refresh rate of a CRT is the number of times per second the image is redrawn. It is typically 60 per second for raster displays. As the refresh rate decreases, flicker develops because the eye can no longer integrate the individual light pulses coming from a pixel. The refresh rate above which a picture stops flickering and fuses into a steady image is called the critical fusion frequency (or) CFF.

 

29. In homogenous coordinate system (x, y, z) the points with z = 0 are called

(A) Cartesian points

(B) Parallel points

(C)Origin point

(D) Point at infinity

Ans:- D

 

Explanation:-

In homogenous coordinates, we add a third coordinate to a point. Instead of being represented by a pair of numbers(x,y) each point is represented by a triple(x,y,w). At the same time, we say that two sets of homogenous coordinates(x,y,w) and (x’,y’,w’) represent the same point if and only if one is a multiple of the other. Thus (2,3,6) and (4,6,12) are the same points represented by the different coordinate triples. Also, at least one of the homogenous coordinates must be nonzero : (0,0,0) is not allowed. If the w coordinate is nonzero, we can divide through by it(x,y,w) represents the same point as (x/w,y/w,1). When w is nonzero, we normally do this division, and the numbers x/w and y/w are called the Cartesian coordinates of the homogenous points. The points with w=0 are called points at infinity. So, the correct answer is D.

 

30. If 40 black lines interleaved with 40 white lines can be distinguished across one inch, the resolution is

(A) 40 line-pairs per inch

(B) 80 line-pairs per inch

(C) 1600 lines per inch

(D) 40 lines per inch

 

Ans:- A

Explanation:-

Resolution is the number of distinguishable lines per inch that a device can create. Resolution is defined as the closest spacing at which adjacent black and white lines can be distinguished by observers. If 40 black lines interleaved with 40 white lines can be distinguished across one inch, the resolution is 80 lines per inch or 40 line-pairs per inch. So, the correct answer is A.

31. Images tend to be very large collection of data. The size of memory required for a 1024 by 1024 image in which the colour of each pixel is represented by a n-bit number, (in an 8 bit machines) is

(A) n X 8 MB

(B) n / 8 MB

(C) (1024 X 1024 ) / 8 MB

(D) 1024 MB

 

Ans:- B

 

Explanation:-

Look at the options which are not going to be correct at all. Eliminate the wrong answers to get the right answer. Every pixel is represented by a n-bit number, the value of n is not mentioned. So, we rule out C and D options completely. So, it can be either A or B. But it is not A because the n-bit number is not going to be multiplied with 8 for a 8 bit machine. So, the correct answer is B.

 

32. Arrays in C language can have _________ with reference to memory representation.

(A) n-subscripts

(B) two-subscripts

(C) only one subscript

(D) three subscripts only

 

Ans:- C

 

Explanation:-

With reference to memory representation, even a two-dimensional array subscript is going to be converted into a single subscript for accessing or referring the memory location. So, it will be option C.

 

33. Refer the points as listed below :

(a) What are the operator precedence rules ?

(b) What are the operator associativity rules ?

(c) What is the order of operand evaluation ?

(d) Are there restrictions on operand evaluation side effects ?

Which of the above must be considered as primary design issues

for arithmetic expressions ?

(A) (a), (b) and (c)

(B) (a), (c) and (d)

(C) (a), (b) and (d)

(D) (a), (b), (c) and (d)

 

Ans:- C

Explanation:-

The options (a),(b) and (d) makes sense, but option (c) is not so clear. There is no order on the operand evaluation. It is decided by the operator precedence and associativity. So, the correct answer is C.

 

34. Horn clauses are special kinds of propositions which can be described as

(A) Single atomic proposition on left side.

(B) Single or multiple atomic proposition on left side.

(C) A single atomic proposition on left side and a single atomic proposition on right side.

(D) A single atomic proposition on left side or an empty left side.

 

Ans:- D

Explanation:-

A Horn clause is a unique kind of proposition which has either one single proposition on the left hand side or an empty proposition. When a Horn clause does contain a proposition on the left side, it is sometimes refered to as a headed Horn clause. The Horn clause is named after Alfred Horn who studied this type of propositional clause (Horn, 1951).

35.Which of the following is/are the fundamental semantic model(s) of parameter passing ?

(A) in mode

(B) out mode

(C)in-out mode

(D) all of the above

 

Ans:- D

 

Explanation:-

The semantic model(s) of parameter passing are in,out and inout. The actual parameters are brought in, moved out, or brought in and moved out respectively.