When monochromatic light of wavelength 600 nm is used in Young's double slit experiment, the fifth order bright fringe is formed at 6 mm from the central bright fringe on the screen. If the experiment is conducted with light of wavelength 400 nm from the central bright fringe, the third order bright fringe will be located at

The position of the direct image obtained at O, when a monochromatic beam of light is passed through a plane transmission grating at normal incidence is shown in figure. The diffracted images A, B, and C correspond to the first, second and third order diffraction. When the source is replaced by another source of shorter wavelength,

In Young’s double slit experiment, the separation between the slits is halved and the distance between the screen is doubled. The fringe width is

In a diffraction pattern due to a single slit of width $$a$$, the first minimum is observed at an angle $$30 \Upsilon$$ when light of wavelength $$500 \mathrm{~nm}$$ is incident on the slit. The first secondary maximum is observed at an angle of