17
2-49. Rest time.
1. B
2. C
3. D
4. E
2-50. Pulse duration.
1. A
2. B
3. D
4. E
2-51. Pulse-repetition time.
1. B
2. C
3. D
4. E
2-52. Which of the following ratios is used to
determine pulse-repetition frequency
(prf)?
1.
3.
2.
4.
2-53. Average power in a pulse-modulation
system is defined as the
1. power during rest time
2. power during each pulse
3. power during each pulse averaged over
rest time
4. power during each pulse averaged over
one operating cycle
2-54. In pulse modulation, what term is used to
indicate the ratio of time the system is
actually producing rf?
1. Rest cycle
2. Duty cycle
3. Average cycle
4. Transmit cycle
2-55. In a pulse-modulation system, which of
the following formulas is used to figure
the percentage of transmitting time?
1.
3.
2.
4.
2-56. When pulse modulation is used for range
finding in a radar application, which of the
following types of pulse information is
used?
1. Reflected pulse return interval
2. Reflected pulse duration
3. Reflected pulse amplitude
4. Reflected pulse frequency
2-57. In a spark-gap modulator, what is the
function of the pulse-forming network?
1. To store energy
2. To increase the level of stored energy
3. To act as a power bleeder
4. To rapidly discharge stored energy
2-58. The damping diode in a thyratron
modulator serves which of the following
purposes?
1. It discharges the pulse-forming
network
2. It limits the input signal
3. It prevents the breakdown of the
thyratron by reverse-voltage transients
4. It rectifies the input signal
2-59. Compared to a spark-gap modulator, the
thyratron modulator exhibits which of the
following advantages?
1. Improved timing
2. Higher output pulses
3. Higher trigger voltage
4. Operates over a narrower range of
anode voltages and pulse-repetition
rates
