When the distance between the slit and the screen is doubled,what happens to the angular separation between the fringes in a slit diffraction experiment?

Which of the following statements are correct with reference to single slit diffraction pattern?
$(I)$ The central maxima is twice as wide as the secondary maxima.
$(II)$ The intensity of secondary maxima decreases as we move away from the central maxima.
$(III)$ The width of the central maxima is independent of the slit width.
$(IV)$ The intensity of the central maxima is the same as that of the secondary maxima.

The diffraction pattern of light of wavelength $400 \ nm$ diffracting from a slit of width $0.2 \ mm$ is focused on the focal plane of a convex lens of focal length $100 \ cm$. The width of the $1^{\text{st}}$ secondary maxima will be:

$A$ slit of size '$a$' is illuminated by a parallel beam of light of wavelength $\lambda$. The angle at which this light is diffracted is approximately . . . . . . .

Write the condition of $n^{th}$ order maximum in diffraction.

In a single slit diffraction pattern,if the first maxima of light of wavelength $\lambda$ coincides with the first minima of yellow light $(540 \ nm)$,then $\lambda$ is ......... $nm$.