In Young's double slit experiment using red and blue lights of wavelengths 600 nm and 480 nm respectively, the value of n for which the nth red fringe coincides with (n + 1)th blue fringe is

In a Young's double slit experiment the intensity at a point where the path difference is λ/6 (λ being the wavelength of the light used) is I. If I₀ denotes the maximum intensity. I/I₀ is equal to 

The resolution limit of the eye is 1. At a distance of x km from the eye, two persons stand with a lateral separation of 3 metres. For the two persons to be just resolved by the naked eye, x should be

λ_a and λ_m are the wavelengths of a beam of light in air and in a medium respectively. If θ is the polarising angle, the correct relation between λ_a , λ_{m and θ is}

Light appears to travel in a straight line because

The velocity of light in diamond, glass and water decreases in the following order:

If a star is moving towards earth,then the lines are shifted towards

A slit of width a is illuminated by white light. The first minimum for red light will fall at 30^o, when a is

The maximum number of possible interference maxima for slit-separation equal to twice the wavelength in Young's double slit experiment, is

In Young's experiment, the ratio of maximum and minimum intensities in the fringe system is 9:1. The ratio of amplitudes of coherent sources is