The 'Facsimile Transmission (FAX)' involves

Important Questions on Communication Systems

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Gamma Question Bank for Medical Physics>Chapter 25 - Communication Systems>Assignment>Q 5

The intensity of a light pulse travelling along an optical fibre decreases exponentially with distance according to the relation $I=I_0{e}^{-0.0693x}$where $x$ is in $\mathrm{km}$ and $I_0$  is intensity of incident pulse. The intensity of pulse reduces to $\frac{1}{4}$ after travelling a distance

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Gamma Question Bank for Medical Physics>Chapter 25 - Communication Systems>Assignment>Q 6

Numerical aperture of an optical fibre (w.r.t. air) having core and cladding refractive indices $n_1$ and $n_2$ respectively is

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Gamma Question Bank for Medical Physics>Chapter 25 - Communication Systems>Assignment>Q 7

On a particular day, the maximum frequency reflected from the ionosphere is $10 \mathrm{MHz}.$ The maximum electron density in ionosphere is

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Gamma Question Bank for Medical Physics>Chapter 25 - Communication Systems>Assignment>Q 8

An optical fibre having core of refractive index $\sqrt{3}$ and cladding of refractive index $1.5$ is kept in air. The maximum angle of acceptance is

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Gamma Question Bank for Medical Physics>Chapter 25 - Communication Systems>Assignment>Q 9

A ground receiver station is receiving a signal at $100 \mathrm{MHz}$ transmitted from a ground transmitter at a height of $300 \mathrm{m}$ located at a distance of $1000 \mathrm{km}.$ It is coming via
$\left(\text{Radius of earth is}, R=6400 \mathrm{km}\right)$

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Gamma Question Bank for Medical Physics>Chapter 25 - Communication Systems>Assignment>Q 10

If ${\mu }_1$ ${\mu }_2$ are the refractive indices of the material of core and cladding respectively of an optical fiber, then

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Gamma Question Bank for Medical Physics>Chapter 25 - Communication Systems>Assignment>Q 11

A transmitting antenna at the top of a lower has a height $32 \mathrm{m}$ and the height of the receiving antenna is $50 \mathrm{m}$. What is maximum distance between them for satisfactory communication in line of sight mode ?

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Gamma Question Bank for Medical Physics>Chapter 25 - Communication Systems>Assignment>Q 12

Broadcasting antennas are generally