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Alternating Current — Physics STD 12 Science — Question

Gujarat BoardEnglish MediumSTD 12 SciencePhysicsAlternating Current2 Marks
Question
Distinguish between ‘sky wave’ and ‘space wave’ modes of propagation. Why is the sky wave mode of propagation restricted to frequencies up to 40 MHz?
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Answer

Space Wave Sky Wave
In space wave mode, the waves travel in straight line directly from transmitter to receiver in. Reflected by Ionosphere.
Because frequencies is greater than 40 MHz, penetrate the ionosphere.
Alternate Answer
There frequencies (greater than 40 MHz) are not reflected by the ionosphere).

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