TU Bachelor of Computer Application 5th Semester Computer Graphics and Animation (CACS305) MCQs

Q: If an object is scaled uniformly with a scaling factor S_x = S_y, where 0 < S_x < 1, what happens to the object?

Correct Answer: It shrinks uniformly.. A scaling factor between 0 and 1 reduces the coordinates, causing the object to shrink uniformly.

Q: During the in-out test in Sutherland Hodgman algorithm, we save the ___.

Correct Answer: intersection point with the edge boundary and the second point. In the Sutherland-Hodgman polygon clipping algorithm, depending on the vertex classification, we save the intersection point and/or the second point.

Q: What will be the scaled point if it is scaled with scaling factors S_x and S_y relative to a reference point (x_r, y_r)?

Correct Answer: x' = x_r + (x - x_r)S_x, y' = y_r + (y - y_r)S_y. Scaling relative to a fixed point involves translating to the origin, scaling, and translating back: x' = x_r + (x - x_r)S_x and y' = y_r + (y - y_r)S_y.

Q: Which color model is subtractive, meaning higher values are associated with darker colors rather than lighter ones?

Correct Answer: CMY. CMY (Cyan, Magenta, Yellow) is a subtractive color model used in printing where adding colors subtracts light, resulting in darker values.

Q: In the depth buffer method, what is the use of refresh buffer?

Correct Answer: To store the intensity value of color at each position (x, y). In the depth-buffer (z-buffer) hidden surface removal algorithm, the refresh buffer stores the color/intensity values for each pixel (x, y).

Q: Which of the following is a primary disadvantage of a raster scan display compared to vector scan display?

Correct Answer: Lines appear jagged due to pixel-based quantization.. Raster scan displays map primitives onto a grid of pixels, causing aliasing or jagged lines due to pixel-based quantization.

Q: To rotate a 3D object about an arbitrary axis that does not pass through the coordinate origin, what is the first step required for it?

Correct Answer: Translate the object so the rotation axis passes through the origin.. The first step in arbitrary axis rotation is translating the axis (and object) so that the rotation axis passes through the coordinate origin.

Q: What is the original point if it is reflected relative of the diagonal line y=x such that reflected point is (5, 6)?

Correct Answer: (6, 5). Reflection about the line y = x swaps the x and y coordinates. Thus, if the reflected point is (5, 6), the original point is (6, 5).

Question 1

If the region code for a point is 0010, then the point lies at ___.

Accepted Answer

Correct Answer: Right to the clipping window. In the Cohen-Sutherland outcode format (TBRL: Top-Bottom-Right-Left), 0010 represents the Right bit set.

Question 2

In which of the following method the visibility is decided point by point at each pixel position on the projection plane?

Accepted Answer

Correct Answer: Image space method. Image space visibility detection methods determine visibility at each pixel position on the projection plane (screen).

Question 3

If an object is scaled uniformly with a scaling factor S_x = S_y, where 0 < S_x < 1, what happens to the object?

Accepted Answer

Correct Answer: It shrinks uniformly.. A scaling factor between 0 and 1 reduces the coordinates, causing the object to shrink uniformly.

Question 4

During the in-out test in Sutherland Hodgman algorithm, we save the ___.

Accepted Answer

Correct Answer: intersection point with the edge boundary and the second point. In the Sutherland-Hodgman polygon clipping algorithm, depending on the vertex classification, we save the intersection point and/or the second point.

Question 5

What will be the scaled point if it is scaled with scaling factors S_x and S_y relative to a reference point (x_r, y_r)?

Accepted Answer

Correct Answer: x' = x_r + (x - x_r)S_x, y' = y_r + (y - y_r)S_y. Scaling relative to a fixed point involves translating to the origin, scaling, and translating back: x' = x_r + (x - x_r)S_x and y' = y_r + (y - y_r)S_y.

Question 6

Which color model is subtractive, meaning higher values are associated with darker colors rather than lighter ones?

Accepted Answer

Correct Answer: CMY. CMY (Cyan, Magenta, Yellow) is a subtractive color model used in printing where adding colors subtracts light, resulting in darker values.

Question 7

In the depth buffer method, what is the use of refresh buffer?

Accepted Answer

Correct Answer: To store the intensity value of color at each position (x, y). In the depth-buffer (z-buffer) hidden surface removal algorithm, the refresh buffer stores the color/intensity values for each pixel (x, y).

Question 8

Which of the following is a primary disadvantage of a raster scan display compared to vector scan display?

Accepted Answer

Correct Answer: Lines appear jagged due to pixel-based quantization.. Raster scan displays map primitives onto a grid of pixels, causing aliasing or jagged lines due to pixel-based quantization.

Question 9

To rotate a 3D object about an arbitrary axis that does not pass through the coordinate origin, what is the first step required for it?

Accepted Answer

Correct Answer: Translate the object so the rotation axis passes through the origin.. The first step in arbitrary axis rotation is translating the axis (and object) so that the rotation axis passes through the coordinate origin.

Question 10

What is the original point if it is reflected relative of the diagonal line y=x such that reflected point is (5, 6)?

Accepted Answer

Correct Answer: (6, 5). Reflection about the line y = x swaps the x and y coordinates. Thus, if the reflected point is (5, 6), the original point is (6, 5).

TU BCA 5th Semester — 2026 BOARD EXAM — Computer Graphics and Animation MCQs

TRIBHUVAN UNIVERSITY

OFFICE OF THE DEAN

Group A (Multiple Choice Questions)

1. If the region code for a point is 0010, then the point lies at ___.

2. In which of the following method the visibility is decided point by point at each pixel position on the projection plane?

3. If an object is scaled uniformly with a scaling factor S_x = S_y, where 0 < S_x < 1, what happens to the object?

4. During the in-out test in Sutherland Hodgman algorithm, we save the ___.

5. What will be the scaled point if it is scaled with scaling factors S_x and S_y relative to a reference point (x_r, y_r)?

6. Which color model is subtractive, meaning higher values are associated with darker colors rather than lighter ones?

7. In the depth buffer method, what is the use of refresh buffer?

8. Which of the following is a primary disadvantage of a raster scan display compared to vector scan display?

9. To rotate a 3D object about an arbitrary axis that does not pass through the coordinate origin, what is the first step required for it?

10. What is the original point if it is reflected relative of the diagonal line y=x such that reflected point is (5, 6)?

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