Question

The lens bounded by two spherical surfaces curved inwards is

• A. biconvex
• B. biconcave
• C. plano-convex
• D. plano-concave

Answer 1

The Correct Option is B

A lens is a transparent medium bounded by two surfaces, both of which can be curved or one can be curved while the other is flat. The nature of the lens is determined by the curvature of these bounding surfaces.

In this case, the question describes a lens with two spherical surfaces curved inwards. These inwardly curved surfaces indicate that the lens is concave on both sides. Such a lens is known as a "biconcave" lens.

The properties of biconcave lenses include:

• They diverge light rays that pass through them.
• They are typically used in applications where light needs to be spread out, such as in eyeglasses for nearsightedness.
• The focal length of the biconcave lens is negative, indicating its diverging nature.

Therefore, the correct answer is: biconcave

Answer 2

A lens that is bounded by two spherical surfaces that are both curved inwards (concave towards the outside) is called a biconcave lens.
This type of lens is thinner at the center and thicker at the edges. It diverges light rays that pass through it, making it a diverging lens.

Final Answer: biconcave