Television
TRUE/FALSE
1. Video systems form pictures by a scanning process.
ANS: T
2. The NTSC system is used in North America.
ANS: T
3. The NTSC system is used in Europe.
ANS: F
4. The NTSC system is used in Japan.
ANS: T
5. The PAL system is no longer used in much of the world.
ANS: F
6. The SECAM system is used in Europe.
ANS: T
7. In North America, TV uses 60 frames a second.
ANS: F
8. NTSC systems use an interlaced scan.
ANS: T
9. The standard TV aspect ratio is 5:3.
ANS: F
10. The electron beam in a TV CRT is blanked during horizontal retrace.
ANS: T
11. The electron beam in a TV CRT is blanked during vertical retrace.
ANS: T
12. The standard analog TV signal is called composite video.
ANS: T
13. A few commercial TV stations broadcast RGB video.
ANS: F
14. Most color monitors for personal computers use RGB video.
ANS: T
15. The luminance signal controls the brightness of a scan line.
ANS: T
16. The standard synchronization for TV is called positive sync.
ANS: F
17. The sync pulses are said to be "blacker than black".
ANS: T
18. The negative peak of a video signal occurs during a sync pulse.
ANS: T
19. The peak video signal occurs at the blanking level.
ANS: F
20. The duration of the vertical blanking pulse identifies which picture field is present.
ANS: F
21. Closed-caption signals can be sent during the vertical blanking time.
ANS: T
22. Horizontal and vertical resolution in a TV system are determined in the same way.
ANS: F
23. The resolution seen by a viewer depends to a certain extent on the TV receiver.
ANS: T
24. Horizontal resolution is equal to the number of visible scan lines.
ANS: F
25. Resolution is proportional to bandwidth.
ANS: T
26. Because of the way people perceive color, any color can be made with red, green, and blue.
ANS: T
27. NTSC color television is not compatible with NTSC monochrome television.
ANS: F
28. In an NTSC color TV system, luminance is derived from the RGB signals.
ANS: T
29. Horizontal resolution for color in NTSC is much less than it is for luminance.
ANS: T
30. NTSC uses a suppressed-carrier system to add color information to the video signal.
ANS: T
31. NTSC uses a type of amplitude modulation for the video signal.
ANS: T
32. A standard video broadcast channel is about 4.5 MHz wide.
ANS: F
33. The audio signal in NTSC video uses FM.
ANS: T
34. Color NTSC receivers use a "color-burst" oscillator to create the color signals.
ANS: F
35. A standard broadcast video signal reaches zero level twice per frame.
ANS: F
36. An analog television receiver uses a type of superheterodyne circuit.
ANS: T
37. The accelerating voltage applied to the CRT in a TV receiver is several thousand volts.
ANS: T
38. Color TVs use a higher accelerating voltage than do monochrome receivers.
ANS: T
39. The CRTs commonly used in TV receivers use electrostatic deflection.
ANS: F
40. The "yoke" is part of the deflection circuit.
ANS: T
41. Color TV receivers do not have a "raster".
ANS: F
42. There is very high voltage at the flyback transformer in a TV receiver.
ANS: T
43. Most of the supply voltages in a TV receiver come from the horizontal output transformer.
ANS: T
44. A typical color CRT contains three electron guns.
ANS: T
45. A typical monochrome CRT contains a "shadow mask".
ANS: F
46. In a color CRT, "purity" means each electron beam hits the correct color phosphor.
ANS: T
47. "Aquadag" is a color phosphor.
ANS: F
48. "Ultor" is a color phosphor.
ANS: F
49. In a CATV system, the main antenna is at the "head end".
ANS: T
50. Like a PSTN central office, the typical CATV system is configured as a star network.
ANS: F
51. Noninterlaced scanning is called "progressive" scanning.
ANS: T
52. HDTV uses the same aspect ratio as standard NTSC.
ANS: F
53. An HDTV signal cannot fit into the bandwidth of a standard broadcast TV channel.
ANS: F
54. Digital encoding and compression play a significant role in HDTV.
ANS: T
55. The FCC has set the phase-out of analog TV broadcasting for the year 2006.
ANS: T
56. Color CRTs emit X rays.
ANS: T
MULTIPLE CHOICE
1. NTSC stands for:
a. National Television Systems Commission
b. National Television Systems Committee
c. National Television Systems Council
d. Nippon Television Systems Commission
ANS: B
2. The NTSC specification was drawn up by the:
a. FCC c. EIA
b. IRE d. IEEE
ANS: C
3. RGB stands for:
a. Red-Green Burst c. Red-Green Bandwidth
b. Red-Green Brightness d. Red-Green-Blue
ANS: D
4. The number of scan lines in an NTSC signal is:
a. 525 c. 1024
b. 625 d. 1250
ANS: A
5. The number of NTSC frames sent per second is:
a. 25 c. 50
b. 30 d. 60
ANS: B
6. The number of NTSC fields sent per second is:
a. 25 c. 50
b. 30 d. 60
ANS: D
7. The aspect ratio of a standard TV receiver is:
a. 3 : 4 c. 525 : 625
b. 4 : 3 d. 625 : 525
ANS: B
8. Luminance refers to:
a. brightness c. chroma
b. contrast d. raster
ANS: A
9. Luminance is measured in:
a. foot-candles c. IRE units
b. lumins d. NTSC units
ANS: C
10. The maximum luminance level is called:
a. max white c. all white
b. peak white d. whiter than white
ANS: B
11. The blanking level corresponds to a luminance of:
a. white c. whiter than white
b. black d. blacker than black
ANS: B
12. The sync pulse level corresponds to a luminance of:
a. white c. whiter than white
b. black d. blacker than black
ANS: D
13. The vertical blanking pulse is serrated to:
a. maintain horizontal sync c. equalize the DC level
b. maintain vertical sync d. all of the above
ANS: A
14. When measured in lines, horizontal resolution:
a. is greater than vertical resolution
b. is about the same as vertical resolution
c. is less than vertical resolution
d. horizontal resolution is not measured in lines
ANS: B
15. The smallest picture element is called a:
a. dot c. pixel
b. pic d. none of the above
ANS: C
16. In a color TV receiver, Y I Q refers to:
a. luminance signal, in-phase color component, quadrature phase color component
b. composite color signal, in-phase color component, quadrature phase color
component
c. composite video signal, in-phase video component, quadrature video color
component
d. a method of demodulating stereo sound
ANS: A
17. Compared to the luminance signal, the horizontal resolution for color is:
a. much greater c. much less
b. about the same d. resolution does not apply to color
ANS: C
18. The modulation used for the video signal in a standard NTSC color TV receiver is:
a. SSB c. suppressed-carrier AM
b. vestigial sideband AM d. FM
ANS: B
19. The modulation used for the audio signal in a standard NTSC color TV receiver is:
a. SSB c. suppressed-carrier AM
b. vestigial sideband AM d. FM
ANS: D
20. The modulation used for the chroma signal in a standard NTSC color TV receiver is:
a. SSB c. suppressed-carrier AM
b. vestigial sideband AM d. FM
ANS: C
21. The function of the "color burst" is to:
a. detect the presence of a color video signal
b. regenerate the color sub-carrier
c. to synchronize the color demodulation line by line
d. all of the above
ANS: D
22. SAP stands for:
a. separate audio program c. sync amplitude pulse
b. separate audio pulse d. sync audio pulse
ANS: A
23. The horizontal output transformer is also called:
a. the isolation transformer c. the flyback transformer
b. the video transformer d. the yoke
ANS: C
24. Compared to a monochrome CRT, the accelerating voltage on a color CRT is:
a. about the same c. much lower
b. much higher d. color CRTs use magnetic acceleration
ANS: B
25. Deflection in CRTs used in TV receivers is done:
a. magnetically for both vertical and horizontal
b. electrostatically for both vertical and horizontal
c. electrostatically for vertical and magnetically for horizontal
d. magnetically for vertical and electrostatically for horizontal
ANS: A
26. AFPC stands for:
a. allowed full picture chroma c. automatic frequency and picture
control
b. automatic frequency and phase control d. none of the above
ANS: B
COMPLETION
1. ____________________ is a conductive coating on both the inside and outside of the CRT in a TV.
ANS: Aquadag
2. The ____________________ standard for TV has been in use since 1953.
ANS: NTSC
3. Video systems form pictures by a ____________________ process.
ANS: scanning
4. During the horizontal blanking interval, the electron beam ____________________ from right to left.
ANS: retraces
5. The NTSC specifies a ____________________ video signal.
ANS: composite
6. The ____________________ ratio of a CRT screen is the ratio of width to height.
ANS: aspect
7. Brightness information is called ____________________.
ANS:
luma
luminance
8. Color information is called ____________________.
ANS:
chroma
chrominance
9. The blanking period before the sync pulse is called the front ____________________.
ANS: porch
10. Odd and even fields are identified by the ____________________ of the vertical sync pulse.
ANS: position
11. Each horizontal scan line takes ____________________ microseconds, not including blanking.
ANS: 62.5
12. Horizontal blanking lasts ____________________ microseconds.
ANS: 10
13. Vertical blanking lasts about ____________________ milliseconds.
ANS: 1.3
14. Picture elements are called ____________________.
ANS: pixels
15. The maximum number of scan lines under NTSC is ____________________.
ANS: 525
16. The human eye is most sensitive to the color ____________________.
ANS: green
17. The color sub-carrier frequency is approximately ____________________ MHz.
ANS: 3.58
18. SAP stands for ____________________ audio program.
ANS: separate
19. The second anode of a CRT is often called the ____________________.
ANS: ultor
20. The accelerating voltage for a color CRT is about ____________________ kV.
ANS: 20 to 30
21. The inside of a CRT's face-plate is coated with ____________________ to generate the picture.
ANS: phosphor
22. The horizontal output transformer is called the ____________________ transformer.
ANS: flyback
23. A good way to separate luma from chroma is to use a ____________________ filter.
ANS: comb
24. The color ____________________ turns off the color circuitry when a color TV is receiving a monochrome
signal.
ANS: killer
25. Signal levels in cable TV systems are usually measured in ____________________.
ANS: dBmV
26. The antenna for a CATV system is located at the ____________________ end.
ANS: head
27. A ____________________ shows a color-bar signal with predetermined levels and phases.
ANS: vectorscope
28. Color intensity is called ____________________.
ANS: saturation
29. The ____________________ of the chroma signal represents the color hue.
ANS: phase
30. The ____________________ controls in a color TV adjust the electron beams to strike the correct color
phosphor dots.
ANS: purity
31. The ____________________ controls in a color TV adjust the electron beams to strike the correct triad of
phosphor dots.
ANS: convergence
