In YDSE, two wavelengths of `500 nm and 700 nm` are used. What is the minimum their maxima coincide ? Take `D//d = 10^(3)`, symbols have standard meaning.

Answer

C

Explanation

At the place where maxima for both the walengths coincide, y will be same for both the maxima, i.e.,
`(n_1lamda_1D)/(d)=(n_2lamda_2D)/(d)`implies(n_1)/(n_2)=(lamda_1)/(lamda_2)=(700)/(500)=(7)/(5)`
Minimum integral value of `n_2`is 5.
`:'` Minimum distance of maxima of the wavelengths from central fringe
`(n_2lamda_2D)/(d)=5xx700xx10^(-9)xx10^(3)=3.5mm`