Question

The image of an object is found to be upright and reduced in size, what type of mirror or lens is used to produce such an image?
A. Concave mirror and converging lens
B. Convex mirror and converging lens
C. Concave mirror and diverging lens
D. Convex mirror and diverging lens

Answer 1

Hint : The upright and reduced images are formed by mirror or lenses which converge the incident light on them. Find out which type of mirror and lens will converge the incoming parallel beam of light. The reduced size image can be produced by other types of mirror and lenses also but that image is not upright. The nature of an image also depends upon the distance of the object from the mirror or lens. Carefully analyse the nature of image depending upon the object distance for each pair given in the option.

Complete step by step solution :
The concave and convex mirrors are two types of curved mirrors.
1. Concave mirrors:
Concave mirrors are curved mirrors with a concave side (inner side) polished. The parallel beam of light gets converged at the focal point when it gets reflected from the mirror. They produce a real and virtual, erect and inverted, diminished, same-sized, and magnified image depending upon the position of the object on the principal axis.
2. Convex mirrors:
Convex mirrors are curved mirrors with a convex side (outer side) polished. A parallel beam of light gets diverged when it is incident on the mirror and they appear to be coming from a single point called the focal point of the mirror. They produce a virtual, erect, and diminished image and the decrease in size of the image depends on the position of the object in front of the mirror.
There are two main types of lenses, the convex lens, and the concave lens.
1. Convex lens:
A convex lens is thicker at the center and thinner at the edges. It converges the parallel beam of light at a single point called a focal point of the lens. Hence it is also called a converging lens. Depending upon the position of the object it can produce real and virtual, magnified and diminished images.
2. Concave lens:
A concave lens is thinner at the center and thicker at the edges. It diverges the parallel beam of the light incident on it. Hence it is also called a converging lens. Depending upon the position of the object it can produce only virtual, erect, and diminished images.
Thus, a concave mirror and converging lens are used to produce an upright and reduced in size image

So option A. (Concave mirror and a converging lens) is correct.

Note : Do not get confused between these two types of mirrors and lenses. Many times students get confused between their shapes. A simple way to remember their shapes is to remember their applications. It is easy to visualize their shapes once you understood their principle of working. Concave mirrors are used where we want to converge light and convex mirrors are used where we want to diverge the light. Convex lenses are used in telescopes, microscopes, and in many applications. Concave lenses are used in eyeglasses and contacts.