Lens | MCQs

Explanation

• The principal axis is a horizontal line that passes through the centre of the lens, perpendicular to its surface.
• It is the central axis around which the lens is symmetrical.

Explanation

• The optical centre is the point within a lens where a ray of light passes through without changing its direction or path.
• This point is located at the centre of the lens, on the optical axis.

Explanation

Concave lenses are also known as diverging lenses, as they spread out light rays and diverge them away from a single point.

Explanation

A converging lens (also known as a convex lens) refracts parallel rays of light and converges them at a single point, called the focal point.

Explanation

• A telescope is an instrument that gathers light from distant sources.
• Such as stars, planets, galaxies, and other celestial objects.
• It allowing us to study and observe them in greater detail.

Explanation

• The lens is responsible for refracting (bending) light to focus it onto the retina.
• It changes shape to adjust the focal length, allowing the eye to focus on objects at varying distances.
• This enables all light rays entering the eye to meet at a single point on the retina, creating a clear image.

Explanation

• The cornea is the transparent, dome-shaped surface at the front of the eye.
• It helps focus light by bending (refracting) it towards the lens.