6
1-48. What determines the bandwidth of an
AM wave?
1. The carrier frequency
2. The number of sideband frequencies
3. The lowest modulating frequency
4. The highest modulating frequency
1-49. If an 860-kilohertz AM signal is
modulated by frequencies of 5 and 10
kilohertz, what is the bandwidth?
1. 5 kilohertz
2. 10 kilohertz
3. 15 kilohertz
4. 20 kilohertz
1-50. If a 1-megahertz signal is modulated by
frequencies of 50 and 75 kilohertz, what
is the resulting maximum frequency
range?
1. 925,000 to 1,000,000 hertz
2. 925,000 to 1,075,000 hertz
3. 975,000 to 1,025,000 hertz
4. 1,000,000 to 1,075,000 hertz
1-51. If an rf carrier is 100 percent AM-
modulated, what will be the rf output
when the modulating signal is (a) at its
negative peak and (b) at its positive
peak?
(a)
0
1.
(b) 2 times the amplitude of the
unmodulated carrier
2.
(a) 0
(b) 1/2 the amplitude of the
unmodulated carrier
(a)
1/2 the amplitude of the
unmodulated carrier
3.
(b) 1/2 the amplitude of the
unmodulated carrier
(a)
1/2 the amplitude of the
unmodulated carrier
4.
(b) 2 times the amplitude of the
unmodulated carrier
1-52. In an AM signal that is 100 percent
modulated, what maximum voltage value
is present in each sideband?
1. 1/4 the carrier voltage
2. 1/2 the carrier voltage
3. 3/4 the carrier voltage
4. Same as the carrier voltage
1-53. Overmodulation of an AM signal will
have which, if any, of the following
effects on the bandwidth?
1. It will increase
2. It will decrease
3. It will remain the same
1-54. In a carrier wave with a peak amplitude
of 400 volts and a peak modulating
voltage of 100 volts, what is the
modulation factor?
1.
0.15
2.
0.25
3.
0.45
4.
0.55
1-55. The percent of modulation for a
modulated carrier wave is figured using
which of the following formulas?
1.
3.
2.
4.
1-56. Modulation produced in the plate circuit
of the last radio stage of a system is
known by what term?
1. Low-level modulation
2. High-level modulation
3. Final-amplifier modulation
4. Radio frequency modulation
