For a given slit, ratio of diffraction angle of fringes of first maxima and first minima is......

Options

A. `(1)/(2)`
B. `(2)/(1)`
C. `(2)/(3)`
D. `(3)/(2)`

Answer

D

Explanation

Condition for `m^(th)` order maxima
`d sin theta_(n)=(2m+1)(lambda)/(2)`
`sin theta_(1)=(3lambda)/(2d) " " [ :. m=1]`
Condition for `m^(th)` order minimum
`d sin theta_(m)=(lambda)/(d)`
`(sin theta_(1))/(sin theta_(1))=(3lambda)/(2d)xx(d)/(lambda)=(3)/(2)`
`:. (theta_(1))/(theta_(2))=(3)/(2)`