Question

When all else remains the same, what effect would decreasing the focal length have on a convex lens?

It would cause the lens to produce only real images.
It would cause the lens to produce only virtual images.
It would make the lens stronger.
It would make the lens weaker.

Answer 1

Answer: The correct answer is "it would make the lens stronger".

Step-by-step explanation:

The power of the lens is defined as the reciprocal of the focal length. If the focal length of the smaller then the power of the lens will more and vice versa.

The power of the lens is measured in Diopter.

More the power of the lens, the stronger the lens would be. The power of the lens has an ability to bend the light. Greater the power of the lens, more the refraction of the light will be.

If the focal length of the convex lens is decreased then the convex lens would make the lens stronger.

Therefore, the correct option is "it would make the lens stronger".

Answer 2

Answer;

It would make the lens stronger.

Explanation;

• The focal length is the distance between the optical center or the center of the lens to the focal point of a convex or concave lens.
• The power of the convex lens is lens ability to undertake refraction or bend light. It is given as the reciprocal of focal length.
• Power of the lens = 1/ f; therefore the smaller the focal length the higher the power and the larger the focal length the lower the power.
• Thus; decreasing the focal length of a convex lens makes the lens stronger.