Which of the following statement is NOT correct ? - Vidyadip

MCQ

Which of the following statement is $NOT$ correct ?

A
Ground wave signals are more stable than the sky wave signals.
B
The critical frequency of an ionospheric layer is the highest frequency that will be reflected back by the layer when it is vertically incident
✓
Electromagnetic waves of frequencies higher than about $30\, MHz$ cannot penetrate the ionosphere
D
Sky wave signals in the broadcast frequency range are stronger at night than in the day time

✓

Answer

Correct option: C.

Electromagnetic waves of frequencies higher than about $30\, MHz$ cannot penetrate the ionosphere

c
Above critical frequency $(f_c)$ , an electromagnetic wave penetrates the ionosphere and is not reflected by it

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