In Fresnel's biprism,coherent sources are obtained by ...

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

What causes changes in the colours of soap or oil films for a given beam of light?

$A$ very thin transparent film (like a soap bubble) is viewed in white light. The color of the film appears .......

White light may be considered to be a mixture of waves with $\lambda$ ranging between $3900\ \mathring A$ and $7800\ \mathring A$. An oil film of thickness $10,000\ \mathring A$ is examined normally by reflected light. If $\mu = 1.4$,then the film appears bright for

In a biprism experiment, a steady interference pattern is observed on the screen kept at a distance of $100 \text{ cm}$ using a light of wavelength $5000 \text{ Å}$. Without changing the distance between the virtual sources of the slit, the source of light is replaced by a source of wavelength $6400 \text{ Å}$. Now, to reduce the fringe width by $20\%$ of its initial value, the screen should be moved