Video-Display Devices in Computer Graphics MCQ Questions and Answers
1. In a CRT display, the device used to accelerate and focus the electron beam is called the
A) Control Grid
B) Electron Gun
C) Deflection Coil
D) Phosphor Screen
Answer: B
2. The persistence of a phosphor refers to
A) The time taken for the phosphor to heat up
B) The time taken for emitted light to decay after excitation
C) The refresh rate of the screen
D) The scanning speed of the beam
Answer: B
3. In a raster-scan system, the image is produced by
A) Directing the beam to draw lines selectively
B) Scanning the screen line by line from top to bottom
C) Moving the beam only where needed
D) Refreshing only the changed pixels
Answer: B
4. A random-scan display is also known as
A) Bitmap display
B) Raster display
C) Vector display
D) Matrix display
Answer: C
5. The component that stores the intensity values of all pixels in a display is
A) Display processor
B) Frame buffer
C) Refresh buffer
D) Display controller
Answer: B
6. The refresh rate of a display device is measured in
A) Seconds per frame
B) Bytes per pixel
C) Milliseconds per refresh
D) Hertz (Hz)
Answer: D
7. A CRT monitor typically operates at a refresh rate of
A) 5–10 Hz
B) 15–30 Hz
C) 60–75 Hz
D) 200–400 Hz
Answer: C
8. The horizontal and vertical deflection in a CRT are controlled by
A) Phosphor screen
B) Control grid
C) Deflection coils or plates
D) Electron gun
Answer: C
9. The glow on a CRT screen is produced by
A) Ionized air
B) Magnetic field
C) Electron beam striking phosphor coating
D) Heat conduction
Answer: C
10. Which type of display does not use electron beams?
A) LCD
B) CRT
C) Random-scan
D) Raster-scan
Answer: A
11. LCD stands for
A) Liquid Crystal Display
B) Linear Cathode Display
C) Light Cathode Device
D) Liquid Cathode Device
Answer: A
12. The basic principle of operation of an LCD is
A) Emission of light from crystals
B) Blocking or allowing light using liquid crystals
C) Magnetic deflection
D) Thermal excitation
Answer: B
13. LED displays are based on
A) Magnetic reflection
B) Light-emitting diodes
C) Plasma excitation
D) Liquid crystals
Answer: B
14. Which of the following has the highest contrast ratio?
A) LCD
B) LED
C) OLED
D) Plasma
Answer: C
15. OLED stands for
A) Organic Light Display
B) Organic Light Emitting Diode
C) Optically Layered Electronic Display
D) Optical Light Enhancement Display
Answer: B
16. In plasma displays, light is generated by
A) Heating filaments
B) Liquid crystal refraction
C) Ionized gas discharge
D) Magnetic fields
Answer: C
17. Which display type is known for deep blacks and thin form factors?
A) CRT
B) Plasma
C) OLED
D) LCD
Answer: C
18. The smallest addressable unit on a display screen is a
A) Line
B) Character
C) Pixel
D) Segment
Answer: C
19. The term “resolution” in display devices refers to
A) Screen brightness
B) Number of pixels in horizontal and vertical directions
C) Refresh frequency
D) Display color depth
Answer: B
20. A screen resolution of 1920×1080 is commonly known as
A) 2K
B) HD Ready
C) Full HD
D) Ultra HD
Answer: C
21. The number of bits used to represent color information per pixel is called
A) Refresh depth
B) Color depth
C) Frame rate
D) Intensity level
Answer: B
22. The RGB color model is
A) Additive color model
B) Subtractive color model
C) Perceptual model
D) Indexed model
Answer: A
23. The CMY color model is used mainly in
A) Display devices
B) Printing
C) Web graphics
D) Raster-scan monitors
Answer: B
24. The HSV color model represents color in terms of
A) Hue, Saturation, Viscosity
B) Hue, Saturation, Value
C) Hue, Shade, Value
D) Highlight, Saturation, Volume
Answer: B
25. The device that converts digital image data to analog signals for display is
A) DAC Controller
B) Digital-to-Analog Converter (DAC)
C) ADC
D) Display Buffer
Answer: B
26. The main advantage of raster displays over vector displays is
A) High refresh speed
B) Ability to display complex filled images
C) Unlimited resolution
D) Reduced memory usage
Answer: B
27. Random-scan systems are primarily used for
A) Line drawings and engineering applications
B) Video playback
C) Game graphics
D) Bitmap images
Answer: A
28. The display processor is responsible for
A) Converting image description into pixel intensity values
B) Storing data in CPU registers
C) Processing audio output
D) Compressing image files
Answer: A
29. The frame buffer size for a 1024×768 display with 8-bit color is
A) 512 KB
B) 768 KB
C) 786 KB
D) 1 MB
Answer: C
30. The term “pixel clock” refers to
A) CPU speed
B) Rate at which pixels are transmitted to the display
C) Screen refresh timer
D) Vertical retrace interval
Answer: B
31. The time interval between successive refreshes of a screen is called
A) Persistence time
B) Refresh period
C) Frame rate
D) Response time
Answer: B
32. Higher refresh rates result in
A) Reduced flicker
B) Lower resolution
C) Higher brightness
D) Reduced frame buffer usage
Answer: A
33. Interlaced scanning reduces
A) Resolution
B) Flicker without doubling bandwidth
C) Color depth
D) Storage requirements
Answer: B
34. A non-interlaced monitor refreshes
A) Alternate lines
B) Every line sequentially per frame
C) Only visible lines
D) Odd lines only
Answer: B
35. The typical persistence value for CRT phosphor in animation displays is
A) 100 ms
B) 30 ms
C) 1–2 ms
D) 50 ms
Answer: C
36. Frame buffer memory requirement increases with
A) Resolution and color depth
B) Refresh rate only
C) CRT size
D) Screen brightness
Answer: A
37. The visual effect of flicker occurs due to
A) Excessive brightness
B) Low refresh rate
C) High resolution
D) Long persistence
Answer: B
38. For a 24-bit true color display, each pixel uses
A) 8 bits
B) 12 bits
C) 24 bits
D) 32 bits
Answer: C
39. A pixel is a combination of
A) Red, Green, and Blue intensity values
B) Hue and Saturation
C) Luminance only
D) Monochrome signal
Answer: A
40. Which display device consumes the least power?
A) CRT
B) Plasma
C) LCD
D) LED
Answer: C
41. In a CRT, the function of the control grid is to
A) Accelerate electrons
B) Control the intensity of the electron beam
C) Deflect the beam
D) Focus the beam
Answer: B
42. The phosphor coating in a CRT is applied on the
A) Electron gun
B) Deflection coil
C) Base plate
D) Inner surface of the screen
Answer: D
43. The brightness of a pixel on the screen depends on
A) Beam width
B) Refresh rate
C) Intensity of the electron beam
D) Resolution
Answer: C
44. The electron beam in a raster scan display moves
A) Left to right, top to bottom
B) Randomly
C) In circular paths
D) Diagonally
Answer: A
45. The blanking interval in raster scanning refers to
A) Screen refresh period
B) Time taken for the beam to return to start of next line or frame
C) Pixel illumination delay
D) Frame buffer reset
Answer: B
46. The vertical retrace occurs
A) Between two pixels
B) Between two lines
C) Between two frames
D) During scanning
Answer: C
47. The advantage of interlaced scanning is
A) Better color reproduction
B) Reduced flicker with lower bandwidth
C) Increased resolution
D) Faster electron beam
Answer: B
48. The refresh buffer stores
A) Intensity values of pixels for one frame
B) Color model data
C) Image compression ratios
D) Display commands
Answer: A
49. The frame buffer content is read by
A) Display controller
B) CPU directly
C) Display processor
D) GPU shaders
Answer: C
50. The purpose of the lookup table in color displays is
A) Refresh scheduling
B) Beam focusing
C) Mapping pixel codes to RGB intensity values
D) Scanning synchronization
Answer: C
51. The color lookup table is also known as
A) Palette
B) Frame buffer
C) Color grid
D) Raster table
Answer: A
52. The speed at which liquid crystals realign when voltage changes determines the
A) Resolution
B) Refresh rate
C) Response time
D) Persistence
Answer: C
53. Ghosting on an LCD screen is caused by
A) High brightness
B) High resolution
C) Slow response time of pixels
D) Excessive refresh rate
Answer: C
54. LED-backlit LCD displays are more efficient than CCFL-backlit ones because they
A) Use heavier glass panels
B) Operate at higher temperature
C) Consume less power and provide better color control
D) Require analog input
Answer: C
55. The viewing angle in LCDs depends on
A) Voltage supply
B) Orientation of liquid crystal molecules
C) Resolution
D) Pixel clock
Answer: B
56. Which of the following displays offers self-illumination (no backlight needed)?
A) LCD
B) Plasma
C) OLED
D) LED
Answer: C
57. Plasma displays use which gases?
A) Neon and Xenon
B) Hydrogen and Helium
C) Argon and Krypton
D) Oxygen and Nitrogen
Answer: A
58. The disadvantage of plasma displays is
A) High brightness
B) Image burn-in and high power consumption
C) Limited viewing angle
D) Slow response time
Answer: B
59. The refresh rate required to avoid flicker in CRT is at least
A) 20 Hz
B) 60 Hz
C) 15 Hz
D) 30 Hz
Answer: B
60. The display resolution 3840×2160 is known as
A) HD
B) FHD
C) 4K UHD
D) 2K
Answer: C
61. The ratio of screen width to height is called
A) Aspect ratio
B) Resolution ratio
C) Pixel ratio
D) Frame ratio
Answer: A
62. The typical aspect ratio of widescreen monitors is
A) 4:3
B) 3:2
C) 16:9
D) 5:4
Answer: C
63. The brightness of a display is measured in
A) Nits (cd/m²)
B) Lumens per second
C) Hertz
D) Pixels per inch
Answer: A
64. The sharpness of a display depends mainly on
A) Pixel density (PPI)
B) Refresh rate
C) Color model
D) Aspect ratio
Answer: A
65. The relation between frame rate and refresh rate is
A) Always identical
B) Refresh rate must be equal or greater than frame rate
C) Frame rate is always higher
D) No relation exists
Answer: B
66. The persistence of a display affects
A) Flicker perception
B) Color accuracy
C) Resolution
D) Viewing angle
Answer: A
67. Increasing color depth leads to
A) More realistic color representation
B) Lower brightness
C) Reduced refresh rate
D) Fewer shades
Answer: A
68. The human eye cannot detect flicker above approximately
A) 10 Hz
B) 30 Hz
C) 60 Hz
D) 15 Hz
Answer: C
69. A frame buffer of size 1920×1080 with 24-bit color requires approximately
A) 2 MB
B) 4 MB
C) 6 MB
D) 1 MB
Answer: C
70. Anti-aliasing in display systems is used to
A) Smooth jagged edges in images
B) Increase frame rate
C) Enhance brightness
D) Reduce memory size
Answer: A
71. The main cause of “screen tearing” is
A) Low resolution
B) Color distortion
C) Mismatch between GPU frame rate and display refresh rate
D) Low brightness
Answer: C
72. The refresh buffer is also known as
A) Frame buffer
B) Cache buffer
C) Display map
D) Pixel table
Answer: A
73. VR and AR headsets use
A) CRT displays
B) OLED or MicroLED panels
C) Plasma displays
D) Vector displays
Answer: B
74. Persistence in CRT must be chosen carefully to balance
A) Power and heat
B) Flicker and motion blur
C) Resolution and brightness
D) Aspect ratio and contrast
Answer: B
75. A 60 Hz refresh rate means the screen refreshes
A) Once per second
B) 60 times per second
C) Every 60 seconds
D) Every 6 milliseconds
Answer: B
76. The phosphor’s emission color in a CRT depends on
A) Chemical composition of the phosphor
B) Beam current
C) Screen voltage
D) Electron velocity
Answer: A
77. The conversion from RGB to CMY is done by
A) Addition
B) Subtraction (C=1–R, M=1–G, Y=1–B)
C) Division
D) Multiplication
Answer: B
78. The additive primary colors are
A) Red, Green, Blue
B) Cyan, Magenta, Yellow
C) Red, Yellow, Blue
D) Red, Cyan, Green
Answer: A
79. Subtractive primary colors are
A) Red, Green, Blue
B) Cyan, Magenta, Yellow
C) Red, Yellow, Black
D) Blue, Yellow, White
Answer: B
80. The Y in the YUV color model represents
A) Luminance
B) Chrominance
C) Hue
D) Saturation
Answer: A
81. The refresh memory in a display is periodically read by
A) Display controller
B) Keyboard interface
C) CPU
D) GPU cache
Answer: A
82. In a raster-scan system, each pixel is stored in
A) CPU registers
B) Frame buffer memory
C) Main memory
D) Cache memory
Answer: B
83. The conversion of bitmap to analog display signals is handled by
A) CPU
B) Digital-to-Analog Converter (DAC)
C) Memory controller
D) VRAM
Answer: B
84. In double buffering, one buffer is displayed while
A) GPU is idle
B) Next frame is drawn in another buffer
C) Frame rate decreases
D) Screen is cleared
Answer: B
85. The main benefit of double buffering is
A) Elimination of flicker and tearing
B) Reduced color depth
C) Lower brightness
D) Reduced resolution
Answer: A
86. The “pixel aspect ratio” defines
A) Screen shape
B) Ratio of pixel width to height
C) Color intensity ratio
D) Luminance
Answer: B
87. A frame rate of 30 fps means
A) 30 pixels per second
B) 30 Hz refresh
C) 30 images per second
D) 30 lines per second
Answer: C
88. A color lookup table allows
A) Dynamic resolution adjustment
B) Efficient color management with limited memory
C) Refresh control
D) Frame synchronization
Answer: B
89. The “gamma correction” adjusts
A) Brightness non-linearity of display
B) Resolution
C) Color model
D) Refresh rate
Answer: A
90. Which of the following display technologies offers the fastest response time?
A) LCD
B) Plasma
C) OLED
D) LED
Answer: C
91. Which factor does NOT affect the screen’s brightness?
A) Beam current
B) Screen resolution
C) Phosphor efficiency
D) Voltage level
Answer: B
92. The deflection sensitivity of a CRT depends on
A) Deflection system design and beam energy
B) Screen resolution
C) Color model
D) Frame buffer
Answer: A
93. VRAM (Video RAM) is used to
A) Store operating system
B) Buffer CPU instructions
C) Store display frame data
D) Handle network packets
Answer: C
94. The advantage of OLED over LCD is
A) Self-emitting pixels and higher contrast
B) Lower brightness
C) Higher cost and heat
D) More power usage
Answer: A
95. The major disadvantage of OLED is
A) Low brightness
B) Limited lifespan due to organic degradation
C) Poor contrast
D) Slow refresh
Answer: B
96. The visual quality improves as
A) Resolution and color depth increase
B) Frame buffer decreases
C) Refresh rate decreases
D) Gamma correction is off
Answer: A
97. The main purpose of a refresh circuit is to
A) Adjust brightness
B) Maintain display content continuously visible
C) Control pixel clock
D) Synchronize colors
Answer: B
98. In a display pipeline, which component comes first?
A) Frame buffer
B) DAC
C) Display
D) Pixel matrix
Answer: A
99. The refresh rate and frame rate are identical when
A) Each frame is displayed once per refresh
B) Refresh occurs twice per frame
C) Interlacing is used
D) Flicker is high
Answer: A
100. In computer graphics, the display device that uses tiny mirrors to reflect light is
A) Plasma display
B) OLED panel
C) DLP (Digital Light Processing) display
D) LCD panel
Answer: C