What part of the eye protects your eye from scratches?
retina
pupil
cornea
iris

Cornea

Explanation:

The outer layer of the cornea is covered by epithelial cells that protect the surface. A corneal abrasion may result from dragging a piece of debris across the surface and scraping off the epithelial cells.

waves moving from a fast medium to a slow medium will experience a reflection as light travels more slowly than red light. total internal reflection occurs when the critical angle is.

d

explanation:

v=uf/(u-f)

= 5.10/(5-10) convex lens has positive focal length

=50/-5

=-10 cm (formed at other side)