a. both receivers.
b. the transmitter of telephone A.
c. each transmitter and each receiver.
d. the transmitter and receiver of telephone A and the receiver of telephone B.
10. Poling the telephone receiver is not required except in rare, special applications. To pole a receiver, the
connections are arranged so that the
a. direct current is barred from the receiver by the use of a capacitor.
b. flux caused by the direct current aids the flux of the permanent magnet .
c. flux caused by the direct current opposes the flux of the permanent magnet.
d. direct current is barred from the receiver by the use of an induction coil.
11. The induction coil of a telephone must transfer power efficiently from the primary circuit to the secondary
circuit. The type of induction coil that does this best is the
a. solid, open-core type.
c. laminated, open-core type.
b. solid, closed-core type.
d. laminated, closed-core type.
12. When the hand generator is used to signal the operator or another party, the telephone ringer is
disconnected and the generator is connected to the line. This transfer is accomplished by the action of the
a. hookswitch.
c. handset switch.
b. line switch.
d. hand-generator switch.
13. The hand generator is a small ac generator operating on the principle of electromagnetic induction. The
a. speed of rotation.
b. strength of the magnetic field.
c. direction of the magnetic field.
d. direction of motion of the conductor.
14. For the purpose of calculating telephone circuit values, the average frequency of voice currents is
considered to be 1,000 hertz. What is the impedance of the two ringer coils to average voice currents?
410 L2
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