Two sources of light of wavelengths 2500 Å and 3500 Å are used in Young’s double slit expt. simultaneously. Which orders of fringes of two wavelength patterns coincide?

Options

A. `3^(rd)` order of `1^(st)` and `5^(th)` order of `2^(nd)`
B. `7^(th)` order of `1^(st)` and `5^(th)` order of `2^(nd)`
C. `5^(th)` order of `1^(st)` and `3^(rd)` order of `2^(nd)`
D. `5^(th)` order of `1^(st)` and `7^(th)` order of `2^(nd)`

Answer

B