In Fresnel's biprism $(\mu = 1.5)$ experiment,the distance between the source and the biprism is $0.3\, m$,the distance between the biprism and the screen is $0.7\, m$,and the angle of the prism is $1^\circ$. The fringe width with light of wavelength $6000\ \mathring{A}$ will be: (in $, cm$)

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 $\beta$.

In a Fresnel's biprism experiment,the distance between the source and the screen is $1 \, m$ and the distance between the source and the biprism is $10 \, cm$. The wavelength of light is $6000 \, \mathring{A}$. The fringe width is $0.03 \, cm$ and the refracting angle of the biprism is $1^\circ$. Find the refractive index of the material of the biprism.

The colors seen on an oil film floating on the surface of water are due to interference. What should be the order of the thickness of the oil film?

Which of the following phenomena produces the colour in a soap bubble?

In a biprism experiment using sodium light $\lambda_1 = 6000\, \mathring{A}$,an interference pattern is obtained in which $20$ fringes occupy $2\, cm$. On replacing sodium light by another source of wavelength $\lambda_2$ without making any other change,$30$ fringes occupy $2.7\, cm$ on the screen. What is the value of $\lambda_2$ in $\mathring{A}$?