• # question_answer In a single slit experiment, how is the angular width of central bright maximum changes, when (i) the slit width is decreased. (ii) the distance between the slit and the screen is increased. (iii) light of smaller wavelength $\lambda$ is used.

In single slit diffraction pattern, the angular width of central maxima,                         $2\theta =2\lambda /a$                                   ?(i) where, $\lambda$ is wavelength and a is width of slit. Therefore,  (i) when the slit width is decreased, then from Eq. (i), angular width of central bright maximum increases. (ii) when the distance between the slit and the screen is increased, then no change in angular width of central bright maximum. (iii) when the light of smaller wavelength $\lambda$ is used, then angular width of central bright maximum decreases.