Question

A particular colour in the rainbow makes an angle of ${42.7}^{\circ }$ with the line of vision. Identify the colour?

• A. Red
• B. Violet
• C. Green
• D. Yellow

Answer 1

The correct option is A

Red

The line of vision is the line connecting the centre of the rainbow and the eye of the observer. The rays of light incident on the water droplets must be parallel to the line of vision. Each colour ray of the 7 colours of white light spectrum emerging from the water drop makes a definite angle from ${40.8}^{\circ }$ to ${42.7}^{\circ }$. Of these, the higher angle ${42.7}^{\circ }$ is made by the red colour as it appears on top of the rainbow. The violet makes the lower angle of ${40.8}^{\circ }$ as it appears at the bottom of rainbow beacuse of having the least wavelength in the VIBGYOR spectrum.