Computer Graphics MCQ Quiz - Objective Question with Answer for Computer Graphics - Download Free PDF

The hidden surface removal problem in computer graphics refers to the process of identifying which surfaces are visible and which are hidden from the viewer's perspective. Hidden Surface Removal (HSR) problem can also be solved using a Brute Force Rasterization algorithm in a minimal 3D graphics pipeline.

Brute force rasterization algorithm: This algorithm works by dividing the viewing window into small cells (pixels) and calculating the visibility of objects in each cell. This approach can be effective for removing hidden surfaces but can be computationally expensive for complex scenes.

Additional InformationPainter's algorithm: This algorithm works by painting surfaces in order of their distance from the viewer's viewpoint. The closest surface is painted first, followed by the next closest surface, and so on. This algorithm is relatively simple to implement and can work well for simple scenes, but it can produce incorrect results for more complex scenes.

Window Clipping algorithm: This algorithm works by defining a viewing window that only displays objects within the window. Objects that fall outside the viewing window are clipped and not displayed. This algorithm is effective for removing hidden surfaces and can work well for scenes with a limited number of object.

Flood fill algorithm: This algorithm is not typically used for hidden surface removal in 3D graphics, as it is primarily designed for 2D image processing tasks such as filling shapes with color.

Concept:

Transformation refers to the mathematical operations or rules that are applied to a graphical image consisting of the number of lines, circles, and ellipses to change its size, shape, or orientation. It can also reposition the image on the screen. Transformations play a very crucial role in computer graphics.

Types of Transformations:

There are various types of transformations in computer graphics through which an image can be processed, edited ad altered. Some basic and most commonly used types of these transformations are

• Translation
• Rotation
• Scaling
• Reflection
• Shearing

A transformation that slants the shape of an object is called the Shear Transformation. There are two shear transformations X-Shear and Y-Shear. One shifts the X coordinate values and the other shifts the Y coordinate values. However, in both cases, only one coordinate changes its coordinates and the other preserves its values. Shearing is also termed Skewing.

In a three-dimensional plane, the object size can be changed along the X direction, Y direction as well as Z direction.So, there are three versions of shearing.

They are

1)Shearing in x-axis

2) shearing in y-axis

3) shearing in z-axis

\(\left[\begin{array}{l}\rm\bar{x} \\\rm \bar{y} \\ \rm\bar{z} \\\rm\bar{w}\end{array}\right]=\left[\begin{array}{llll}\rm a_1 & \rm b_1 & \rm c_1 & \rm d_1 \\ \rm a_2 & \rm b_2 & \rm c_2 & \rm d_2 \\ \rm a_3 & \rm b_3 & \rm c_3 & \rm d_3 \\ \rm e & \rm f & \rm g & \rm h \end{array}\right]\left[\begin{array}{c} \rm x \\ \rm y \\ \rm z \\ 1 \end{array}\right]\) is called Shear Transformation.

The Correct Answer is option 2.

The correct answer is Wireless mouse uses Radio Frequency (RF) to send signals from the mouse to the computer.

Key Points

• A mouse is a hardware input device of the computer that controls the cursor. It is a pointing device that functions by detecting 2D motion.
• There are different types of mice available such as wireless, optical, Bluetooth, laser etc.
• Wireless mouse uses Radio Frequency (RF) to send signals from the mouse to the computer. Hence option 4 is correct.
• It works with 2.4GHz band radio frequencies which require a radio transmitter and a radio receiver. It is wireless but it needs a USB adaptor to receive commands.
• The radio transmitter is integrated into the mouse and the radio receiver connects to the computer peripheral. It receives the RF signal, decodes them and sends these signals to the computer.

Additional Information

• Logitech manufactured the world's first wireless mouse to use Radio Frequency transmission.
• A Bluetooth mouse uses radio waves to communicate wirelessly with a computer. It has a great range but is less accurate than other mice.
• Bluetooth devices work on frequency hopping techniques.

The correct answer is Movement in an optical mouse is detected by sensing changes in Reflected light.

Key Points

• A mouse is a hardware input device of the computer that controls the cursor. It is a pointing device that functions by detecting 2D motion.
• There are different types of mice available such as wireless, optical, Bluetooth, laser etc.
• An optical mouse is an advanced pointing device that uses Light Emitting Diode (LED) in the place of a mouse ball and Digital Signal Processing (DSP) in the place of an electromechanical transducer.
• In the optical mouse, movement is detected by sensing the changes in reflected light rather than by interpreting the motion of a mouse ball. Hence statement 2 is correct.
• It takes microscopic snapshots of the working surface at the rate of 1000 frames or images per second. If the mouse move, the frame changes.

Additional Information

• Surfaces like glass could reflect the LED too much which affects the variations in the light pattern. Hence the optical mouse cannot be used on glass surfaces.
• A laser mouse is a mouse that uses laser light for pointing.
• A higher DPI mouse is better for gaming as it reduces the input lag while gaming. Less input lag increase accuracy.

The correct answer is ODT.

Key Points

• A bitmap basically describes a type of image. 
• Pixels all the basic sources of information.
• BMP, GIF, JPEG, EXIF, PNG, and TIFF are bitmap file formats.
• Bitmap format commonly used raster graphic format for saving image files. 
• Raster graphics are independent of display devices which means a bitmap image file can be viewed without any graphics adaptor. 
• The file can store a 2D digital image in both monochrome and colour format.

The Correct Answer is Joystick.

 Key Points

• Joy Stick is a  pointing device used to move an object on a screen in any direction.
• It employs a vertical rod mounted on a base with one or two buttons.
• Joysticks are often used to control video games, and usually have one or more push-buttons whose state can also be read by the computer.

 Additional Information

• Optical Mark Reading (OMR)
  • Optical Mark Reading (OMR) is a method of entering data into a computer system.
  • Optical Mark Readers reads pencil or pen marks made in pre-defined positions on paper forms as responses to questions or tick list prompts.
• Visual Display Unit
  • Visual Display Unit is a device for displaying input signals as characters on a screen.
  • The monitor is an example of VDU.
• MIDI (Musical Instrument Digital Interface) controller
  • It is a way to connect devices that make and control sounds — such as synthesizers, samplers, and computers — so that they can communicate with each other.

The correct answer is option 2.

Concept:

A single BUS structure is used to connect the I/O devices. One common bus is utilized to communicate between peripherals and the CPU in a single bus configuration. It has drawbacks owing to the usage of a single common bus.​

• All units are connected to a single bus, so it provides the sole means of interconnection. A single bus structure has the advantages of simplicity and low cost.
• Because only two units may participate in data transmission at the same time, single bus structures have the drawback of the restricted speed.
• This necessitates the use of an arbitration mechanism, as well as the forced waiting of units.
• An example is a communication between the processor and printer.

Hence the correct answer is Single BUS structure.

Additional Information

•  MULTIBUS II is an open system bus architecture for designing general-purpose 8-, 16-, and 32-bit microcomputer systems.

Explanation:

• Some commonly used Input/Output devices are listed in the table below. 

Input device:

• An input device is a piece of hardware used to provide data to a computer used for interaction and control. It allows the input of raw data to the computer for processing.​
• Some of the input devices are
  • ​Keyboard: Keyboard is one of the primary input devices used to input data and commands. It has function keys, control keys, arrow keys, a keypad, and the keyboard itself with the letters, numbers, and commands.
  • Mouse: It is an input device used to control the cursor and coordinates. It can be wired or wireless.
  • Microphone: It is an input device that allows users to input audio into their computers.
  • Scanner: It is an input device that reads an image and converts it into a digital file. A scanner is connected to a computer through a USB.
  • Touchscreen: It is an input device that allows users to interact with a computer using their fingers. It is used widely in laptop monitors, smartphones, tablets, cash registers, and information kiosks.  
  • Plotter: The plotter is the computer's output device that could print graphics as well as accommodate full-size engineering and architectural drawings. Using multiple colored pens, plotters were also able to print in color long before inkjet printers became an alternative.

The correct answer is Red, Green, Blue.

• Red, green, and blue are the primary colours of light—they can be combined in different proportions to make all other colors.
• There are two colour models:
  • Light Color Primaries (Red, Green, Blue).
  • Pigment Color Primaries (Cyan, Magenta, Yellow).

Important Points

• Primary colours make all other colours:
  • Red + Green = Yellow.
  • Green + Blue = Cyan.
  • Blue + Red = Magenta.
• There are three Secondary Colors (S'): Orange, Green, Violet.
• There are six Tertiary Colors (Ts): Red-Orange, Yellow-Orange, Yellow-Green, Blue-Green, Blue-Violet, Red-Violet.
  • Tertiary is formed by mixing a primary with a secondary.

Additional Information

• In terms of wavelengths, visible light ranges from about 400 nm to 700 nm.
• light with a wavelength of about 400 nm is seen as violet, and light with a wavelength of about 700 nm is seen as red.

Key Points

• The inner surfaces of human eyes contain photoreceptors—specialized cells that are sensitive to light and relay messages to the brain.
  • There are two types of photoreceptors: cones (which are sensitive to colour) and rods (which are more sensitive to intensity).
  • Humans are able to see an object when light from the object and enters their eyes and strikes these photoreceptors.

The correct answer is Laser Printers and Inkjet Printers.

Key Points

• Non-Impact Printers:
  • These printers do not allow direct contact between ribbon and paper. Use laser, electrophotographic, electrostatic, chemical, or inkjet technology.
  • Examples: Laser Printers, Inkjet Printers, Thermal printers, Bubblejet Printers.

Additional Information

•  Impact Printers:
  • These printers allow direct contact between ribbon and paper.
  • In these printers, printing is done by character dye.
  • Examples: Dot Matrix Printers, Daisy Wheel Printers, Drum Printers.

The correct answer is Both 1 and 2.

Key Points

• Multimedia is the use of a computer to present and combine text, graphics, audio, and video with links and tools that allow the user to navigate, interact, create and communicate.
• Multimedia is broadly divided into linear and non-linear multimedia.

Additional Information

• Linear Multimedia
  • The end-user cannot control the content of the application.
  • A linear multimedia application lacks all the features with the help of which, a user can interact with the application such as the ability to choose different options, click on icons, control the flow of the media, or change the pace at which the media is displayed.
  • It works very well for providing information to a large group of people such as at training sessions, seminars, workplace meetings, etc.
• Non-Linear Multimedia
  • The end-user is allowed the navigational control to rove through multimedia content at his own desire.
  • The user can control the access of the application.
  • Non-linear offers user interactivity to control the movement of data. For example computer games, websites, self-paced computer-based training packages, etc.

The correct answer is option 1.

Key Points

 Horizontal retracing is also known as vertical retracing. The beam returns to the left of the screen at the end of each scan line to show the next scan line.

∴ Hence the correct answer is The path an electron beam takes when returning to the left side of the CRT.

• In perspective projection, objects that are far away appear smaller, and objects that are near appear bigger.
• A perspective projection of an object is often considered more realistic than a parallel projection, since it more closely resembles human vision and photography
• Parallel projection is equivalent to a perspective projection where the viewer is standing infinitely far away
• Perspective projections preserve straight lines.

Frame buffer has 10 bits per pixel and 8 bits are allocated for each R, G and B components.

As frame buffer has 10 bits. So, entries in color lookup table = 2¹⁰

8 bits for each component. Collectively 24 bits for all three components.

It means 24/8 = 3 bytes are for R, G and B component collectively.

Size of color look up table = number of entries in look up table × size of each entry