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Current Electricity

Question

Why sky wave propagation of electromagnetic waves cannot be used for TV transmission?
Suggest two methods by which range of TV transmission can be increased.

Answer

TV signals have frequencies of 100-200 MHz, which penetrate ionosphere (frequencies > 30 MHz cannot be used), hence sky wave propagation cannot be used for TV transmission.

Two methods by which range of TV transmission can be increased:
(a) use of tall antenna
(b) use of repeaters between transmitters and receivers (line-of-sight transmission).