Derive referaction formula (for object in air and image in the denser medium ) for refraction of light at a spherical surface

What is the unit of measurement of refracting power of a spherical surface?

Define pole of a spherical refracting surface.

An object in air is viewed through a denser medium. Does the object appear closer to the surface?

Draw a ray diagram showing the formation of the image by a point object on the principal axis of a spherical convex surface separating two media of refractive indices n_(1) and n_(2) , when a point source is kept in rarer medium of refractive index n_(1) . Derive the relation between object and image distance in terms of refractive index of the medium and radium of curvature of the surface. Hence obtain the expression for lens-maker's formula in the case of thin convex lens.

According to Huygens' principle, during refraction of light from air to a denser medium

Light is travelling from denser medium to rarer medium. Polarising angle of incidence at the surface is

If a ray of light in a denser medium strikes a rarer medium at an angle of incidence i , the angle of reflection and refraction are respectively r and r', if the reflected and refracted rays are at right angles to each other, the critical angle for the given pair of media is