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96. In FDM, how many voice band channels are

there in a jumbo group?

A. 7200 C. 10,800

b. 3600 D. 1000

97. Using NTSC standard, what is the aural

carrier frequency of UHF TV channel 28?

A. 558.75 MHz C. 553.75 MHz

B. 559.75 MHz d. 555.25 MHz

98. A parametric amplifier must be cooled

_______.A. to provide better amplification

B. to be operational because it cannot operate

at room temperature

c to improve the noise performance

D to increase the bandwidth

99. Which of the following frequencies is

wrong?

A. 60 Hz for vertical sync and scanning

B. 15,750 Hz for horizontal sync scanning

C. 31,500 Hz for equalizing pulses and

serrations in the vertical sync pulse

D. 31,000 Hz for the vertical scanning

frequency

100. An optic fiber is made of glass with a

refractive index of 1.54, and clad with anotherglass with refractive index of 1.50. Launching

takes place from air. Calculate the numerical

aperture of the fiber.

a. 0.352 C. 0.0352

B. 0.00352 D. 3.52