Elenco AM/FM Radio Kit - Manual (Page 61)

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QUIZ - FM RADIO SECTION
INSTRUCTIONS: Complete the following examination, check your answers carefully.
Answer s: 1. C , 2. B , 3. A, 4. A, 5. A, 6. B, 7. C, 8. A, 9. D , 10. B
1. The FM broadcast band is . . .
r
A) 550 - 1,600kHz.
r
B) 10.7MHz.
r
C) 88 - 108MHz.
r
D) 98.7 - 118.7MHz.
2. The maximum audio frequency used for FM is ...
r
A) 7.5kHz.
r
B) 15kHz.
r
C) 20kHz.
r
D) 10.7MHz.
3. The frequency of the modulating signal
determines the . . .
r
A) number of times the frequency of the
carrier changes per second.
r
B) maximum deviation of the FM carrier.
r
C) maximum frequency swing of the FM
carrier.
r
D) amount of amplitude change of the FM
carrier.
4. The AFC circuit is used to ...
r
A) automatically hold the local oscillator on
frequency.
r
B) maintain constant gain in the receiver to
prevent such things as fading.
r
C) prevent amplitude variations of the FM
carrier.
r
D) automatically control the audio
frequencies in the receiver.
5. The ratio detector transformer is tuned to ...
r
A) 10.7MHz.
r
B) 88MHz.
r
C) 455kHz.
r
D) 10.9MHz.
6. The ratio detector is used because ...
r
A) it is sensitive to noise.
r
B) it is insensitive to noise.
r
C) it provides amplification.
r
D) it doesn’t need a filter.
7. The device most often used for changing the
local oscillator frequency with the AFC voltage is
a ...
r
A) feedthrough capacitor.
r
B) variable inductor.
r
C) varactor.
r
D) trimmer capacitor.
8. The capacitance of a varactor is determined by ...
r
A) the voltage level.
r
B) the amount of current in the circuit.
r
C) the signal strength of the RF carrier.
r
D) the amount of resistance in the circuit.
9. Limiting in FM receivers is the process of ...
r
A) removing interfering FM stations.
r
B) providing greater station selectivity.
r
C) separating the FM stations from the AM
stations.
r
D) removing noise from the FM carrier.
10. A detector circuit that does not require a limiter is
a ...
r
A) slope detector.
r
B) ratio detector.
r
C) Travis detector.
r
D) Foster-Seeley detector.