On a rainy day,a small oil film on water shows brilliant colours. This is due to:

When petrol leaking from a vehicle falls on a rain-wet road,colours are observed. This is due to the.......... of light.

In a biprism experiment, the fifth dark fringe is obtained at a point. $A$ thin transparent film of refractive index '$\mu$' is placed in one of the interfering paths. Now, the $7^{th}$ bright fringe is obtained at the same point. If '$\lambda$' is the wavelength of light used, the thickness of the film is equal to:

If prism angle $\alpha = 1^\circ$,refractive index $\mu = 1.54$,distance between screen and prism $b = 0.7\,m$,distance between prism and source $a = 0.3\,m$,and wavelength $\lambda = 180\pi\,nm$,then in a Fresnel biprism,find the value of fringe width $\beta$.

The beautiful iridescent (like a rainbow) colors on the wings of a tropical or morpho butterfly are due to

What is the minimum thickness of a thin film required for constructive interference in the reflected light from it (in $ nm$)? Given, the refractive index of the film $= 1.5$, wavelength of the light incident on the film $= 600 \, nm$.