Question

Observe the figure.
(A) Which colors are formed on the screen?
(B) Explain the phenomenon that causes the formation of an array of colors?
(C) Which colors are denoted by ‘A’ and ‘B’?
(D) Which color deviates the most?
(E) Which color deviates the least?
(F) Different colors undergo different deviations. Why?

Answer 1

Hint: We know that white light consists of seven different colors. All the colors combine together to form plain white light. The seven colors are nothing but the rainbow colors – VIBGYOR.
When light passes through any medium, it gets refracted. It is nothing but bending of light when it passes from one medium to another medium.
The colors are VIBGYOR – red, orange, yellow, green, blue, indigo, violet in the descending order of their wavelengths. They form the visible spectrum. The one with the highest wavelength deviates the most.

Complete Step By Step Answer:
We know that when white light passes through a prism or a glass surface, refraction takes place and the white light gets separated into seven components known as VIBGYOR. This process is known as dispersion.
Let’s answer all the questions.
(A) VIBGYOR – Violet, Indigo, Blue, Green, Yellow, Orange and Red.
(B) Dispersion is a phenomenon. The separation of white light into its seven constituent colors is called dispersion.
(C) A is the one with least wavelength – Violet and B is the one with highest wavelength – Red.
(D) The color with the least wavelength deviates the most, which is Violet.
(E) The color with the highest wavelength deviates the least, which is Red.
(F) All the seven colors have different wavelengths and frequencies. Hence the angle of deviation is different for every color. The deviation caused by the prism increases with decrease in wavelength.

Note:
We need to remember that there are seven different colors in white light. We also need to remember their sequence with increasing wavelength.
Students have a misconception that the color with highest wavelength deviates the most. This is wrong. It’s the opposite. The color with the least wavelength deviates the most.