`lamda_(1)` and `lamda_(2)` are used to illuminated the slits. `beta_(1)` and `beta_(2)` are the corresponding fringe widths. The wavelength `lamda_(1)` can produce photoelectric effect when incident on a metal. But the wavelength `lamda_(2)` cannot produce photoelectric effect. The correct relation between `beta_(1)` and `beta_(2)` is

Options

A. `beta_(1) lt beta_(2)`
B. `beta_(1) = beta_(2)`
C. `beta_(1) gt beta_(2)`
D. `beta_(1) ge beta_(2)`

Answer

A

Explanation

Fringe width, `beta = (lamdaD)/(d)`
`:. beta prop lamda :. (beta_(1))/(beta_(2))= (lamda_(1))/(lamda_(2))`
`lamda_(1)` can produce photoelectric effect and `lamda_(2)` cannot produce photoelectric effect
`rArr lamda_(1) lt lamda_(2) :. beta_(1) lt beta_(2)`