Name the colours of the visible spectrum.

Give one example in nature where we can see the dispersion of white light.

Which of the following phenomena of light are involved in the formation of a rainbow?

$A$ beam of white light falling on a glass prism gets split up into seven colours marked $1$ to $7$ as shown in the diagram. $A$ student makes the following statements about the spectrum observed on the screen.
$(a)$ The colours at position marked $3$ and $5$ are similar to the colour of the core of a hard-boiled egg and the colour of the sky respectively. Is the statement made by the student correct or incorrect? Justify.
$(b)$ Which of the two positions correspond closely to the colour of $(i)$ a solution of potassium permanganate,$(ii)$ danger or stop signal lights?

The longest and the shortest wavelengths (in $\mu m$) for red and violet light are respectively:

Describe an experiment to discuss the recombination of dispersed light.