Question

In Fraunhofer diffraction experiment, $L$ is the distance between screen and the obstacle, $b$ is the size of obstacle and $A$. is wavelength of incident light. The general condition for the applicability of Fraunhofer diffraction is

• A. $\frac{b^2}{L \lambda} >>1$
• B. $\frac{b^2}{L \lambda} = 1$
• C. $\frac{b^2}{L \lambda} <<1$
• D. $\frac{b^2}{L \lambda} \neq 1 $

Answer 1

Answer: (C)

The general condition for Froun hofer diffraction is $\frac{b^2}{L\lambda} << 1$.