The diffraction fringes obtained from a single slit are.....

Two slits are made $1 \; mm$ apart and the screen is placed $1 \; m$ away. What should the width of each slit be to obtain $10$ maxima of the double-slit pattern within the central maximum of the single-slit pattern (in $; mm$)? Blue-green light of wavelength $500 \; nm$ is used.

Assertion: $A$ coloured spectrum is seen when we look through a muslin cloth.
Reason: It is due to the diffraction of white light on passing through fine slits.

In a single slit diffraction experiment,for a wavelength of light $\lambda$,the half-angular width of the central maxima is $\theta$. For a wavelength of light $p\lambda$,the half-angular width of the central maxima is $q\theta$. What is the ratio of the half-angular widths of the first secondary maxima in the first case to the second case?

Light is incident normally on a diffraction grating through which the first order diffraction is seen at $32^\circ$. The second order diffraction will be seen at

$A$ 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 . . . . . . .