In Young's double slit experiment using monochromatic light of wavelength '$$\lambda$$', the maximum intensity of light at a point on the screen is $$\mathrm{K}$$ units. The intensity of light at point where the path difference is $$\frac{\lambda}{3}$$ is

$$\left[\cos 60^{\circ}=\sin 30^{\circ}=\frac{1}{2}\right]$$

If two sources emit light waves of different amplitudes then

Two coherent sources of wavelength '$$\lambda$$' produce steady interference pattern. The path difference corresponding to 10$$^{th}$$ order maximum will be

In Young's experiment, fringes are obtained on a screen placed at a distance $$75 \mathrm{~cm}$$ from the slits. When the separation between two narrow slits is doubled, then the fringe width is decreased. In order to obtain the initial fringe width, the screen should be moved through.