a. switchboard.
c. repeating amplifier.
b. patching panel.
d. hybrid coil circuit.
3. The function of the balancing network of the hybrid coil circuit shown in
figure 3-2 is to
a. minimize line loss.
b. balance amplifier gain.
c. prevent singing of circuits.
d. eliminate hysteresis of transformer core.
4. Selection of the correct value of resistance for the balancing resistor in
a hybrid coil circuit is important because an incorrect value will cause
a. losses of signal energy.
b. feedthrough between talk and listen paths.
c. noise buildup through magnetic coupling of the coils.
d. transfer of signals from the switchboards to the lines.
5. The function of a hybrid coil circuit is similar to the function of a
a. balanced bridge.
c. repeating coil.
b. phantom circuit.
d. loading coil.
6. Assume that a level of -2 dbm enters a hybrid coil circuit on the two-wire
line from the switchboard. If the hybrid circuit has normal loss, the level
going out on the send line will be approximately
a. -1 dbm.
c. -4 dbm.
b. -2 dbm.
d. -6 dbm.
7. One disadvantage of a hybrid coil in a telephone network carrying data
signals is that the hybrid circuit may introduce excessive
a. loss.
c. resistance.
b. delay.
d. feedthrough.
8. Assume that a telephone user hears a number of echoes on a long-distance
telephone network. The echo that has traveled the longest distance causes the
most interference because this echo is
a. delayed the longest.
b. louder than the others.
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