Question

why do we see seven colours when white light disperses? which colours deviates the least?

Answer 1

Violet color deviates the least

Answer 2

WE SEE SEVEN DIFFERENT COLOUR THAT ARE "'VIBGYOR"' (ACRONYM FOR VIOLET, INDIGO, BLUE, GREEN, YELLOW, ORANGE, RED) WHEN WHITE LIGHT IS PASSED THROUBH A GLASS PRISM BECAUSE OF THE PHENOMENON OF DISPERSION OF WHITE LIGHT IN WHICH WHITE LIGHT IS DISPERESD INTO IT'S COMPONENTS BECAUSE EACH COLOUR HAS ITS OWN WAVELENGTH.

LONGEST WAVELENGTH- RED

SHORTEST WAVELENGTH- VIOLET.

THE SPEED OF LIGHT OR COLOUR DEPENDS UPON THE WAVELENGTH. IF WAVELENGTH OF A COLOUR IS LARGE,THE SPEED OF THE COLOUR IS ALSO LARGE.THUS,EACH COLOUR OF LIGHT TRAVELS WITH DIFFERENT SPEED IN A GIVEN MEDIUM. THE SPPED OF RED COLOUR IS MORE THAN SPEEDD OF ORANGE COLOUR IN A MEDIUM. THE SPEED OF ORANGE COLOUR IS MORE THAN THE SPEED IOF YELLOW COLOUR AND SO ON. THEREFOR , THE SPEED OF RED COLOUR IN A MEDIUM IS THE HIGHEST AND THE SPEED OF VIOLET COLOUR IS THE LEAST. HENCE,ALL COLOURS OF WHITE LLIGHT ARE REFRACTED BY DIFFERTENT AMOUNT WHILE PASSING THROUGH GLASS PRISM. THEREFROE, WHEN A WHITE LIGHT PASSESS THROUGH A GLASS PRISM DIFFERENT CONSTITUENT COLOURS COME OUT OF THE PRISM AT DIFFEREBT ANGLE. THIS GIVES A RISE TO DISPERION OF WHITE LIGHT. THE LIGHT WHISH WE SEE ARE CALLED SPECTRUM i.e.,VIBGYOR




or
White light is composed of light of different wavelengths (colors) i.e. violet, indigo, blue, green, yellow and red. Red has the highest wavelength and violet the lowest. ... The color red therefore devaites the least since it has maximum wavelength and colorviolet deviates the most since it has the least wavelength.