Thin Lenses

Question 1

Forms of lenses

Answer 1

Plano concave |( & plano convex |)

Equi convex () & equi concave )(

Meniscus ((

Question 2

Define:

Front vertex

Back vertex

Answer 2

Front vertex - where the optical axis of the lens intersects the front surface

Back vertex - where the optical axis of the lens intersects the back surface

Question 3

Define:

Optical axis

Centre thickness

Answer 3

Optical axis - perpendicular line to the surfaces that passes through the centre of the lens, joining the centre of curvatures.

Centre thickness - is the thickness of a lens in the centre

Question 4

Define:

Radii of curvature

Centre of curvature

Answer 4

Radii of curvature - is the distance from the centre of the sphere (centre of curvature) to the edge.

Centre of curvature - is the centre of the sphere in which a lens makes a part of

Question 5

Define:

Optical centre

Answer 5

Optical centre - centre of a lens in which the principle axis passes through and the point where light rays pass through without deviation & aberrations