Class 10 Physics
Refraction through Lens
Refraction of parallel ray:
A parallel ray converges at focus of a convex lens and diverges from the focus of a concave lens.
Fig: Ray parallel to principal axis
Fig: Ray parallel to principal axis
Refraction of ray passing through the Principal focus:
A ray passing through principal focus emerges parallel to the principal axis after refraction from a convex lens.
Fig: Ray passing through focus
Fig: Ray passing through focus
A ray passing through the principal focus emerges parallel to the principal axis after diverging from a concave lens.
Ray passing through the optical centre of lens:
Ray passing through the optical centre of convex and concave lens emerges in same direction without any deviation.
Fig: Ray passing through O
Fig: Ray passing through O
Converging lens: A convex lens is known as converging lens because parallel rays converge at its focus.
Fig: Converging Lens
Diverging lens: A concave lens is known as diverging lens because parallel rays appear to diverge from the focus; after refraction.
Fig: Diverging Lens