Question

(b) In the primary rainbow, does the observer see the green bow at a lower or higher angle than the yellow bow? Explain

(i) why this is, and

(ii) explain the main physical processes producing a primary rainbow

Answer 1

b) i) in the primary rainbow red light scatter in a large angle and blue light is at a low angle, so according to the wavelength pattern of VIBGYOR, green will have a lower angle than yellow. each water droplets act as a sphere and scatter the light according to their wavelength red has the highest wavelength(635-700 nm) in the visible spectrum and blue (450-485nm) is minimum.

ii) main physical processes involved in the formation of the primary rainbow is refraction and reflection. red appears in the outer side and blue in the inner side of the primary rainbow arc, and it is produced when the light gets refracted during the entry into the droplet and reflected inside the drop and again refracts when it leaves the water droplets. so, the sunlight undergoes two refractions and one reflection to produce this primary rainbow.