Answer:
The answer is "[tex]1.144 \times 10^{-4} \ m[/tex]".
Explanation:
[tex]w=\frac{2.44 \lambda L}{D}\\\\D=\frac{2.44 \lambda L}{w}\\\\[/tex]
[tex]=\frac{2.44 \times 633 \times 10^{-9}\times 4 }{0.054}\\\\=\frac{6178.08\times 10^{-9}}{0.054}\\\\=1.144 \times 10^{-4} \ m[/tex]
