a. 37.6 ohms.
b. 79.0 ohms.
Hint: Refer to tables I and II in
Appendix A.
c. 113 ohms.
d. 157 ohms.
10. Complete cancellation of capacitive reactance by inductive reactance in a
telephone line is not desirable because
a. howling or singing may result from resonance.
b. line current drops suddenly at the frequency of resonance.
c. line impedance rises to a high value, attenuating the signal.
d. the sharply increased loss at resonance causes distortion in the voice
signal.
11. When we load a telephone line to reduce attenuation, we add
a. inductance in series with the line.
b. capacitance in series with the line.
c. inductance in parallel with the line.
d. capacitance in parallel with the line.
12. The loading curve in figure 6 of Appendix B shows variation in attenuation
of a transmission line at different frequencies. What effect does this loading
have on voice power as the signal passes through the line?
a. The attenuation increases sharply above cutoff, reducing voice power
above this frequency.
b. The attenuation increases sharply below cutoff, reducing voice power
below this frequency.
c. The attenuation decreases sharply above cutoff, allowing more voice
power to pass.
d. The attenuation decreases sharply below cutoff, allowing more voice
power to pass.
13. The function of a repeater amplifier in a telephone system is to
a. introduce loss.
c. overcome attenuation.
b. reduce distortion.
d. eliminate the need for loading.
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