What color does a red rose appear when green light is incident upon it?

When a light ray travels from an optically denser medium to an optically rarer medium, what is the angle of incidence called at which the angle of refraction becomes $90^{\circ}$?

Name the outermost layer of the eye. What is its function?

Due to atmospheric refraction of light,the Sun appears to rise $................$ its actual sunrise.

Draw a ray diagram showing the refraction of light through a glass prism and mark the following:
$(a)$ Incident ray
$(b)$ Emergent ray
$(c)$ Refracted ray
$(d)$ Angle of incidence
$(e)$ Angle of deviation
$(f)$ Angle of emergence

In which direction is a rainbow formed during the morning hours in the rainy season?