1.

Class XII problemEstimate the distance for which ray optics is a good approximation for an aperture of 4 mm and wavelength 400 nm.

Answer»  The distance for which ray optics is a good approximation is GIVEN by the Fresnel's distance.
aperture, a = 4 MM = 4×10^(-3) m
wavelength, \lambda = 400nm = 400×10^(-9) m

Z_F= \frac{a^2}{ \lambda} = \frac{(4 \times 10^{-3})^2}{400 \times 10^{-9}} =\frac{16 \times 10^{-6}}{4 \times 10^{-7}}=\boxed{40m} 


Discussion

No Comment Found

Related InterviewSolutions