Question

Fresnel distance for an aperture of size a illuminated by a parallel beam of light of wavelength λ, deciding the validity of ray optics is

• A. $\frac{λ}{a^2}$
• B. $λa$
• C. $a^2λ$
• D. $\frac{a^2}{λ}$
• E. $a^2λ^2$

Answer 1

Answer: (C)

$a^2λ$

Answer 2

The correct option is (C) : $a^2λ$