A) 18m
B) 30m
C) 38m
D) 50m
Correct Answer: D
Solution :
\[{{Z}_{F}}=\frac{{{a}^{2}}}{\lambda }\] \[{{Z}_{F}}\to \]Fresnel distance. \[{{Z}_{F}}\simeq \frac{{{(5\times {{10}^{-3}})}^{2}}}{5000\times {{10}^{-10}}}=\frac{25\times {{10}^{-6}}}{5\times {{10}^{-7}}}=50\,m\]You need to login to perform this action.
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