Question

The point near the centre of a thin lens through which a ray of light passes without appreciable deviation is called the:

Options

• Principal focus

• Centre of curvature

• Optical centre

• Pole

Answer 1

The optical centre is the point near the centre of a thin lens through which a ray of light passes without appreciable deviation. This is why a ray passing through the optical centre is used as one of the standard rays for constructing images.