Lights of wavelengths `lambda_(1)=4500 Å, lambda_(2)=6000 Å` are sent through a double slit arrangement simultaneously. Then

Options

A. no interference pattern will be formed
B. the third bright fringe of `lambda_(1)` will coincide with fourth bright fringe of `lambda_(2)`
C. the third bright fringe of `lambda_(2)` will coincide with fourth bright fringe of `lambda_(1)`
D. the fringes of wavelength `lambda_(1)` will be wider than fringes of wavelength `lambda_(2)`

Answer

C

Explanation

Let `p^(th)` bright fringe corresponding to `lambda_(1)` coincides with `q^(th)` bright fringe of `lambda_(2)`
`x=plambda_(1)=qlambda_(2)`
`p/q=lambda_(2)/lambda_(1)=6000/4500=4/3`
`4^(th)` bright fringe of `lambda_(1)` coincides with `3^(rd)` bright fringe of `lambda_(2)`