The phenomenon due to which white light splits into seven colours on passing through a prism is called spectrum.

The phenomenon due to which white light splits up into seven colours, on passing through an equilateral prism is called ______ of light.

The band of seven colours obtained on a screen when white light passes through a prism is called spectrum. ____

A beam of white lighe passing through a hollow prism gives no spectrum.

(a) Draw a ray diagram to explain the term angle of deviation. (b) Wgy do the component colours of incident white light cplit into a spectrum whilepassing through a glass prism, explain. (c) Draw a labelled ray diagram to show the formation of a rainbow.

For refractin of light through a prism

A beam of white light is incident on a hollow prism of glass. Then

When a ray of sun light passes through the prism, each colour of light has its own speed in the glass. The seven colours come out of the prism with different angles of deviation. Red deviates least and blue deviates maximum. Thus a prism can disperse a white light into seven colours which is called colour spectrum. For a thin prism, the angle of deviation is given as delta=(n-1)A . The angle of dispersion is given as phi=delta_(v)-delta_(r) . The dispersive power of a prism is omega=(phi)/(delta_("mean"))=(phi)/(delta_(y)) Using the above ideas, give answer the following questions. A prism has R.I. for violet and red n_(v)=1.523, n_(r)=1.5145 . If the angle of prism is A=2^(@) the dispersive power of the prism is :

Name the colour of white light which is deviated (i) the most, and (ii) the least, on passing through a prism.