This note provides an information about dispersion and spectrometer .When a beam of white light is made to fall on one refracting face of the prism, it splits into seven colours i.e. violet, indigo, blue, green, yellow, orange and red from the base. The phenomenon of the splitting of white light into its constituent colours is called dispersion of light.
This note provides us an information about angular dispersion and deviation without dispersion . When a beam of white light passes through a prism, light of different colours are deviated by different amounts .
This note provides us an information about dispersion without deviation .When white light is incident on the crown glass prism, it is deviated as well as dispersed which fall on the flint glass prism. The deviation produced by crown glass prism for mean colour is equal and opposite to that produced by flint glass prism. So, net deviation produced by the combination for mean colour is zero.
This note provides us an information about chromatic aberrations in lenses .The inability of a lens to focus all colours of light at a single point is called chromatic aberration or axial or longitudinal chromatic aberration. It is measured by the difference in focal lengths between red and violet colours.
This note provides us an information about a spherical aberration in a lens and scattering of light .If a point object is placed on the axis of the large lens, images Ip and Im will be formed by the paraxial and marginal rays respectively. The paraxial rays of light from the image at a longer distance from the lens than the marginal rays. The image is not sharp at any point on the axis.