120. An optical fiber has a specification of 50 ps/km/nm material dispersion whenused with an optical beam from a laser diode at 0.88 pm with AX = 10A. What will be the overall pulse spread in nonoseconds due to material dispersion for a fiber of 2 km length
A.1
B.0.1
C.10
D.100

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121. Higher the angle of acceptance (0a) in a given fiber optic set-up,
A. lower is the magnitude of Numerical aperture as NA = cos OA
B. higher is the magnitude of Numerical aperture as NA = sin OA
C. lower is the fiber length that can be used for a given light power
D. none of these

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122. The channel capacity is exaclty equal to which of the following?
A. Noise rate in the channel
B. Bandwidth of demand
C. Amount of information per second
D. None of the above

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123. In a communication system, noise is most likely to effect the signal in the
A. channel
B. transmitter
C. information source
D. any of the above

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124. Dit is a unit of
A. channel capacity
B. entropy
C. information
D. rate of information

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125. The maximum possible value of entropy is
A.1
B.6
C.10
D. infinity

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126.  Which of the following filters is used only at higher frequency?
A. Half lattice
B. Ladder
C. Crystal gate
D. Full lattice

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