4. The amplitude-frequency response of a loaded line is said to be "flat"
when attenuation is constant over a given frequency range.
The attenuation
curve in figure 6 of Appendix B approaches a flat response over the voice-
frequency range extending between
a. 300 Hz and 3,500 Hz.
c. 3,500 Hz and 3,800 Hz.
b. 300 Hz and 4,000 Hz.
d. 3,800 Hz and 4,500 Hz.
5. A term often used by designers of long-distance trunk circuits is
attenuation constant.
This is a mathematical expression which combines the
effect of the four properties of a telephone line, namely,
a. resistance, leakage, capacitance, and inductance.
b. leakage, capacitance, inductance, and conductance.
c. inductance, conductance, resistance, and leakage.
d. capacitance, inductance, conductance, and resistance.
6. Assume that two telephones 20 miles apart are connected by a wire pair
that has 74 ohms resistance per loop mile (37 ohms per wire). If you measure
the total resistance in the wire with the far end shorted (looped back), the
ohmmeter should read approximately
a. 370 ohms.
c. 1,480 ohms.
b. 740 ohms.
d. 2,960 ohms.
7. The amount of leakage in telephone cables is usually small because the
a. metal sheath is ungrounded.
b. cable pairs are protected from moisture.
c. insulation resistance between wire pairs is infinite.
d. telephone cable is supported by messenger cable rather than by crossarm
8. Unequal attenuation of a telephone line is caused by its electrical
properties. As the frequency rises, the electrical properties that cause less
signal current to arrive at the receiver are
a. inductance and capacitance.
c. resistance and leakage.
b. capacitance and resistance.
d. leakage and inductance.
9. Assume that a telephone line circuit has the equivalent inductance of 6
millihenries and capacitance of 1 microfarad. If the resistance of the line is
157 ohms, the approximate impedance of the circuit at 2,000 Hz is
7
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