Question

a Discuss the difference between the continuous spectrum obtained with a grating and one obtained with a prism. (b). Which color is deviated most in each case? Why?

Answer 1

answer) The differences are as follows-

1) continuous spectrum with a grating uses diffraction and with a prism its done by the principle of dispersion , in diffraction the light changes its direction when it strikes the surface and in prism we need to two medium, the light changes its direction when it goes from one medium to another .

2) in grating the bending of light does not depend upon the material of the object but in prism the bending depends on the material of the medium

3) the grating bends light at a larger angle than compared to prism,

4) the order of spectrum is reverse in grating than compared to prism as the dispersion causes the shorter wavelength of visible light to refract more.

In grating the red color is deviated the most and in prism the violet color deviates the most.

its because in diffraction the bending of light expands in the atmosphere at much larger angle and they interfere with other the light from other sources and which results in constructive interference., so the color with higher wavelength is refracted more in grating which is red and in prism the shorter wavelength deviates the most since dispersion causes the shorter wavelength of light which is violet to deviate most.