Calculate time taken by light to travel 1 cm thickness of glass `(mu = 1.5)`

Light travels through a glass plate of thickness t and having a refractive index mu .If c is the velocity of light in vacuum,the time taken by the ligth to travel this thickness fo glass is

The distance of a galaxy is of the order of 10^25 m. Calculate the order of magnitude of time taken by light to reach us from the galaxy.

Time taken by light to cross nuclear diameter is of the order of

A spherical convex surface of radius of curvature 20 cm, made of glass (mu=1.5) is placed in air. Find the positon of the image formed, if a point object is placed at 30 cm in front of the convex surface on the principal axis.

A small object is enclosed in a spere of glass 7 cm in radius .It si situated 1 cm from the centre and is veiwed from the side to whh it is nearest.where will it appear to be ,if refractive index is 1.4?Also find the appparent position of the oject as seen by an eye looking laong diameter throug greatest thickness of eh glass.

A beam of light strikes a glass sphere of 20 cm diameter converging towards a point 40 cm behind the pole of the spherical surface.Fnd the position of the image,if the refractive index of glass is 1.5.

Green light of mercury has a wavelength 5*5 xx 10^(-5) cm. What is the wavelength in glass,if refractive index of glasss is 1.5?Given, c=3 xx 10^8 m s^(-1) .

A small black dot is marked on the surface of a glass spehre (mu=1.5) and is viewed from the other side.If radius of the sphere is 15 cm,find the position of the image of the dot.

At what angle of incidence will the light reflected from glass (=1.5) be completely polarised?