Two wavelengths λ1 and λ2 are used in Young's double slit experiment ​λ1 and λ2

Question

Two wavelengths \(\lambda_{1}\) and \(\lambda_{2}\) are used in Young's double slit experiment \(\lambda_{1}=450 \mathrm{~nm}\) and \( \lambda_{2}=650 \mathrm{~nm}\). The minimum order of fringe produced by \(\lambda_{2}\) which overlaps with the fringe produced by \(\lambda_{1}\) is n. The value of n is  ____.

Answer 1

Correct answer is : 9

\(\mathrm{n}_{2} \lambda_{2}=\mathrm{n}_{1} \lambda_{1}\)

\(\frac{\mathrm{n}_{2}}{\mathrm{n}_{1}}=\frac{\lambda_{1}}{\lambda_{2}}=\frac{450}{650}=\frac{9}{13}\)

\(\mathrm{n}_{2}=9\)