CHAPTER 4
TEST ITEMS
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Multiple-Choice Questions
1. Frequencies used for radio communication are found __________ the electromagnetic spectrum.
d. throughout
e. nowhere in
2. Which type of wave is not part of the electromagnetic spectrum?
a. Cosmic
b. Light
3. A carrier wave is modulated to
d. travel further.
e. travel more slowly.
4. In radio communication, __________ determines information capacity.
a. channel frequency
5. AM signals can travel much farther at night because of __________ propagation.
a. ground-wave
6. The best location for an FM transmitting antenna is
a. on dry, sandy soil.
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7. A television station’s interference zone is
d. caused by high transmitter power.
e. caused by low transmitter power.
8. The FCC has classified the largest number of AM channels as
a. local.
b. regional.
9. International short-wave radio stations
a. use multiplexing to increase their range.
10. Which of the following is not an advantage that FM radio has over AM radio?
a. Less atmospheric interference.
11. An FM radio station covering a radius of about 60 miles, which is considered a wide range, would be
classified as a __________ radio station.
a. Class A
12. __________ scanning is used in creating a television picture.
a. Field
13. In the U.S., television uses __________ sound.
a. AM
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144. A VHF television channel occupies __________ times as much space on the electromagnetic
spectrum as an AM radio channel.
a. 10
155. Flat screen technology called __________ is used in portable TVs and laptop computers.
a. time base correctors
16. This flat-screen technology uses a grid of tiny channels (pixels) filled with gas, usually a mixture of
neon and xenon.
d. VBI.
e. CRT.
17. An advantage of digital processing is
a. a wider channel requirement than the same signals in analog form.
18. The wholly new television transmission system that will eventually replace the current U.S. system is
commonly called
d. DAB.
e. MUSE.
19. This group advises the FCC on DTV formats.
a. NTSC
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20. In radio transmission, __________ promises to replace U.S. analog radio broadcasting.
21. This system transmits a digital signal on an FM station subcarrier that can be displayed on a special
receiver panel.
a. DARS
True/False Questions
2. Frequency is expressed in terms of cycles per second, or Hertz (Hz), to honor a famous radio
3. When a radio station’s carrier wave is modulated, adjacent frequencies called tangent waves are used.
5. One solution the FCC uses to reduce AM co-channel interference during evening hours is to have
6. AM’s 10-kHz spacing means that channels extend 5 kHz above and below their carrier frequencies.
11. Digital signal processing breaks down an incoming signal into a stream of separate pulses and assigns
123. Radio broadcast data systems will be transmitted on an FM subcarrier for receivers equipped with a
Essay Questions
1. Differentiate among amplitude, length, frequency, and velocity in wave motion.
2. How are ground, direct, and sky waves propagated?
3. How is interference between TV stations minimized?
4. Differentiate between AM and FM signals and their propagation.
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