Question:
Orange light of wavelength $6000 \times 10^{-10} \mathrm{~m}$ illuminates a single slit of width $0.6 \times 10^{-4} \mathrm{~m}$. The maximum possible number of diffraction minima produced on both sides of the central maximum is
Solution:
(198)
For obtaining secondary minima at a point path difference should be integral multiple of wavelength
$\therefore d \sin \theta=n \lambda$
$\therefore \sin \theta=\frac{n \lambda}{d}$
For $n$ to be maximum $\sin \theta=1$
$n=\frac{d}{\lambda}=\frac{6 \times 10^{-5}}{6 \times 10^{-7}}=100$
Total number of minima on one side $=99$
Total number of minima $=198$.