In Young's double slit experiment the ratio of phase difference between light waves reaching the third bright fringe and third dark fringe is

In Young's double slit experiment, the ratio of intensities of light from one slit to the other is $$9: 1$$. If Im is the maximum intensity, what is the resultant intensity when they interfere at phase difference $$\phi$$ ?

In Young's double slit experiment, the intensity of light at a point on the screen where the path difference is $$\lambda$$ is $$\mathrm{K}$$ units ($$\lambda$$ is the wavelength of light used). The percentage change in intensity at a point where the path difference is $$\frac{\lambda}{6}$$ and the above point is

In the Young's double slit experiment $$n^{\text {th }}$$ bright for red coincides with $$(n+1)^{\text {th }}$$ bright for violet. Then the value of '$$n$$' is: (given: wave length of red light $$=6300^{\circ} \mathrm{A}$$ and wave length of violet $$=4200^{\circ} \mathrm{A}$$).