What happens when parallel rays of light fall on a lens making some angle with the principal axis ?

What happens when a pollen grain falls on a stigma?

What happens to a ray travelling parallel to the principal axis ?

What will happen if there is no dispersion of light ?

Draw the ray diagram in the case of formation of virtual image when an object is kept on the principal axis of a concave mirror ?

What will happen if Islets of langerhans fall to function ?

What are the favourite light rays for plants?

Draw a diagram for the given situation. "when the object is at infinity , the parallel rays from the object falling on the eye lens are refracted and they form a point sized image on retina."

What happens to the light ray when a transparent material with two curved surfaces is placed in its path ?