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