Considering interference between two sources of intensities $I$ and $4I$,the intensity at a point where the phase difference is $\pi$ is $(\cos \pi = -1)$.

Two light waves of intensities $I$ and $2I$ superimpose on each other. If the path difference between the light waves reaching a point is $12.5 \%$ of the wavelength of the light,then the resultant intensity at the point is (Both the light waves have same wavelength).

To demonstrate the phenomenon of interference,we require two sources which emit radiation of

Two coherent waves of equal intensity produce a maximum intensity of $100$ units. If the intensity of one of the sources is reduced by $20\%$,then the new maximum intensity will be:

The total energy carried by a light wave when it travels from a rarer to a non-reflecting and non-absorbing medium:

For constructive interference to take place between two monochromatic light waves of wavelength $\lambda$, the path difference should be