Em Waves Question 97
Question: For wave propagation of a $ 10MHz $ signal, what should be the maximum electron density in ionosphere
Options:
A) $ \tilde{\ }1.2\times 10^{12}{{m}^{-3}} $
B) $ \tilde{\ }10^{6}{{m}^{-3}} $
C) $ \tilde{\ }10^{14}{{m}^{-3}} $
D) $ \tilde{\ }10^{22}{{m}^{-3}} $
Show Answer
Answer:
Correct Answer: A
Solution:
[a] If maximum electron density of the ionosphere is $ {N _{\max }} $ per $ m^{3} $ then the critical frequency $ f _{c} $ is given by $ f _{c}=9({N _{\max }})1/2 $
$ \Rightarrow 10\times 10^{6}=9{{(N)}^{1/2}}\Rightarrow N=1.2\times 10^{12}{{m}^{-3}} $
BETA
