Question:1.In the United States, what frequency range is reserved for FM Broadcast Radio?
a. 100-4000 Hz
b.88-108 MHz
c. 400 - 2483.5 MHz
d.530 - 1,620 KHz
2. Why does FM Radio sound better than AM Radio for music?
a. Because FM stations don't transmit as far so the signal is stronger
b. Because only music stations broadcast on FM
c. Because FM is a new technology
d. Because FM broadcast allows modulation frequencies of 100-15,000 Hz.
3.This is a dish antenna with a lot of gain, designed to communicate with deep space satellites. The radio antenna pictured above has motors that point it at satellites. Why does the antenna need to move to work?
a. Putting big motors on things always makes them better
b. It needs to change its orientation so it will not look directly at the sun.
c. It needs to point at the satellites to keep the focused waves on the satellites
d. The magnetic field of the earth interferes with the electromagnetic waves generated. By moving the antenna this can be corrected for.
4. Why do radio stations use 1/4-wave antenna?
a. They are really small compared to other antennas.
b. They radiate in all radial directions equally so they reach people all around
c. They are really easy to make
d. They are really common, so why not?
5. 'The Jack' radio station in Dallas broadcasts on 100.3 FM. They use a 1/4-wave antenna to broadcast. How long is this antenna?
a. 1.992 m
b. 0.254 m
c. 0.747 m
d. 15.3 m
6.The sampling rate used for storing music on a CD is ________?
a.8,000 samples/sec
b. 48,000 samples/sec
c. 22,050 samples/sec
d. 44,100 samples/sec
7.What does AM mean in the field of radio and television?
a. After Me.
b. It is morning.
c.Alpha Median
d.Amplitude Modulation
8.A WiFi radio wave with frequency of 5.2 GHz has a wavelength of about _________.
a. 5.77 cm
b. 17.5 m
c.12.5 cm
d. 17.5 cm
9. The distance traveled by a wave in one period is called _______?
a. Period
b. Speed of wave
c. Amplitude
d. Wavelength
e. Frequency
10. The electric field (E) and the magnetic field (H) are perpendicular to each other in an electromagnetic wave. True or False
a. False
b.True
c. E and H are unrelated.
d. Unknown
11. If the oscillator output is modulated by audio frequencies up to 10 kHz, the frequency range occupied by the side bands will be
a. 711.9 kHz to 712.1 kHz
b. 71.2 kHz to 71.20 kHz
c. 692 kHz to 732 kHz
d. 702 kHz to 722 kHz
12. The television luma Y signal has maximum percentage of ________.
a. red color
b. red and blue colors
c. blue color
d. green color
13. Sound waves are electromagnetic waves.
a. Unknown
b. True
c. Not applicable
d. False
14. A parabolic dish antenna is a(n) _______ antenna.
a. bidirectional
b. omnidirectional
c. split directional
d. unidirectional
15. _______ are used for cellular phone, satellite, and wireless LAN communications.
a. Radio waves
b. Light waves
c. mm waves
d. Infrared waves
16. An image is sampled to give a 128x128 array of pixels. If this digital image is stored with 64 gray levels, it requires ________bits of storage. (Hint: how many bits in a sample gives 64 possibilities?)
a. 8192
b. 98304
c. 1048576
d. 12288
17. For FM radio signals, which statement is correct?
a. Both the phase and the audio quadrant carry the information.
b. Changes in amplitude carry the information, and the carrier frequency stays the constant.
c. Changes in the amplitude and the frequency carry the information.
d. Changes in the carrier frequency carry the information, and amplitude stays the constant.
18.A WiFi radio wave with frequency of 2.4 GHz has a wavelength of about _________.
a. 17.5 cm.
b.17.5 m.
c. 19 mm.
d. 12.5 cm.
19. 802.11b is a WiFi standard. In the US 12 channels are available for its use. Each channel is _____________ wide.
a. 90.1 MHz
b. 20+2 MHz
c. 200 KHz.
d. 50 MHz
20. Which statement below provides the best definition of a pixel?
a. A pixel is the smallest addressable element in an image.
b. A pixel only includes gray-scale data.
c.Pixel is a combination of 'pix' (picture) and 'el' (elements).
d. A pixel includes red, green and blue data in the image from a digital camera.
21. The power at a receiver at a distance of 1000 meters from a transmitter is 0.0002 watts. If the receiver is moved to a distance of 10,000 meters, what is the measured power?
a. 0.000002 watts
b. 0.00002 watts
c. 0.002 watts
d. 0.00000002 watts
22. A __________ is a device that converts electromagnetic wave into a plane wave propagating in free space.
a. Receiving antenna
b. Transmitting antenna
c. Radar
d. Amplifier
23. Isotropic antenna radiates in _____ degrees.
a. 90
b. 180
c. 360
d. 270
24. Antenna gain is ________________.
a. the focusing of energy radiated by the antenna in a certain direction.
b. the power gain required for transmitting electromagnetic waves.
c. distance required to gain for better reception.
d. e antenna wavelength required to transmit.