Question

why total internal reflection happens if a light is passed through right angled prism??​

Answer 1

The refraction happens because different colors have a different wavelength while passing through the glass prism.

The angle if refraction is also different for different colors.

Answer 2

Total internal reflection happens if a light is passed through right angled prism because, white light has 7 colours (VIBGYOR), in which each has different wavelength. Thus the refraction differs for each colour, and the lifht is seperated.

Hope it helps!!