A beam of white light falling a glass prism split up into seven colours marked 1 to 7 as shown in the diagram. A student makes the flowing statements about the spectrum observed on the screen : The colours at position mared 3 and 5 are similar to the colour of the sky and the colour of gold metal, respectively. Is the above statement made by the student correct or incorrect ? Justify.

Which of the above-shown positions corresponds approximately to the colour of (a) a solution of potassium permanganate and (b) 'danger' or stop signal lights ?

Explanation

The colours are in the order : 1: Red, 2 : Orange, 3: Yellow, 4: Green, 5: Blue, 6: Indigo, and 7: Violet
(i) No, Because we know that the sky is blue and colour of gold metal is yellow which correspond to numbers 5 and 3 respectively. The student is stating the colours in reverse order.
(ii) (a) 7. (b) 1.