NEET UG PHYSICS MCQ: COMMUNICATION SYSTEMS

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When electromagnetic waves enter the ionised layer of ionosphere, then the relative permittivity

ie

, dielectric constant dielectric constant of the ionised layer

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Correct option: C

Appears to decrease

The correct answer is C (Appears to decrease) because the refractive index of the ionosphere is related to the electron density, and as electromagnetic waves enter, the effective dielectric constant decreases.

More Questions from COMMUNICATION SYSTEMS

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In the communication systems, AM is used for broadcasting because The maximum and minimum voltage of an amplitude modulated signal are

60 \mathrm{~V}

and

20 \mathrm{~V}

respectively. The percentage modulation index will be: Depth of modulation

\left( {{m_a}} \right)

in terms of

{{\text{E}}_{{\text{max}}}}\,{\text{and}}\,{{\text{E}}_{{\text{min}}}}

is The process of superimposing signal frequency (i.e., audio wave) on the carrier wave is known as The antenna current of an AM transmitter is 8 A when only the carrier is sent, but it increases to 8.93 A when the carrier is modulated by single sine wave. Find the percentage modulation. An audio signal of amplitude one half the carrier amplitude is used in amplitude modulation. Calculate the modulation index?