Question

A manufacturer uses a concave lens instead of a convex lens in a magnifying glass by mistake. What will be the effect on the working of the lens?
A. Images will be blurred
B. Images will be clearer
C. Images will be diminished
D. Images will be further magnified

Answer 1

Hint: Consider the image formation of an object by concave lens and look into the nature and size of image.

Complete step by step answer:
The convex lens is usually used as a magnifying lens for a magnifying glass because when the object is placed at a distance less than the focal length of the lens, we get a magnified virtual image.

In the case of a concave an object placed at distance greater than or less than the focal length of a lens produces a virtual image which is always diminished. So if you use a concave lens for a magnifying glass what you will get is a diminished image of an object.
So the answer to the question is option (C)- Image will be diminished.

Additional Information:
Concave lenses are used in flashlights and high beam lights in order for the light to diverge and cover a large area.
A certain combination of concave lenses are used in camera lenses.

Note: A magnifying glass can be used to focus light, such as to concentrate the sun's radiation to a point so the focused light made by the lens will cause a fire.
If we try to increase the magnification of a magnifying lens more than a certain limit, optical aberrations will occur that will result in the decrease in quality of the image obtained.