In an interference experiment,the phase difference for points where the intensity is minimum is $(n=1, 2, 3, \ldots)$

Two light waves of same intensity superpose at point $P$ with a phase difference of $\pi/3$. The resultant intensity at point $P$ will be?

The wave nature of light can be determined by $......$.

Two light waves having the same wavelength $\lambda$ in vacuum are in phase initially. Then the first wave travels a path $L_{1}$ through a medium of refractive index $n_{1}$ while the second wave travels a path of length $L_{2}$ through a medium of refractive index $n_{2}$. After this the phase difference between the two waves is:

Interference cannot be observed in two sodium lamps of equal power because the two waves do not have a .....

The interference pattern is obtained with two coherent light sources of intensity ratio $n$. In the interference pattern,the ratio $\frac{I_{max} - I_{min}}{I_{max} + I_{min}}$ will be