Oil floating on water looks coloured due to interference of light. What should be the order of magnitude of the thickness of the oil layer in order that this effect may be observed? (in $m$)

What is the effect on Fresnel's biprism experiment when white light is used?

$A$ circular planar wire loop is dipped in a soap solution and after taking it out,held with its plane vertical in air. Assuming the thickness of the film at the top is very small,as sunlight falls on the soap film,the observer receives reflected light. What does the observer see?

When exposed to sunlight,thin films of oil on water often exhibit brilliant colours due to the phenomenon of

White light is incident at an angle of $30^\circ$ on a soap film with a refractive index of $4/3$. The wavelength of the transmitted light is observed to be $6 \times 10^{-5} \, cm$. Find the minimum thickness of the film.

In a biprism experiment,the fringe width is $0.6 \ mm$. The distance between the $6^{th}$ dark fringe and the $8^{th}$ bright fringe on the same side of the central bright fringe is: (in $mm$)