For a parallel beam of monochromatic. Light of wavelength `'lamda'` diffraction is produced by a single slit whose width 'a' is of the order of the wavelength of the lightl. If 'D' is the distance of the screen from the slit, the width of the central maxima will be

Options

A. `(D lamda)/(a)`
B. `(D a)/(lamda)`
C. `(2D a)/(lamda)`
D. `(2D lamda)/(a)`

Answer

D

Explanation

The central maxima lies between the first minima on both sides.
`therefore`The linear width of the central maximum `=2x=(2lamdaD)/(a)`.