Question

Identify the characteristics of the images formed by convex mirrors.
A) Are always real
B) Are always virtual
C) Are only real when the object is placed outside the radius of curvature.
D) Are only virtual when the object is placed outside the focal point.
E) None of the above describes the images formed by the convex mirrors.

Answer 1

Hint: The convex mirror gives the diverged image of an object. Hence it is called the diverging mirror because the incident light originates from the same point and will reflect off the mirror surface and diverge.

Complete step by step answer:
(i) A convex mirror is a spherical mirror as its surface is spherical in shape. The spherical reflecting surface bulges towards the incident light source.
(ii) The convex mirrors only form the virtual images because the light always incident on the backside of the mirror. And the center of curvature, the focal point is out of reach.

Hence we can say that the convex mirror images are always virtual. Therefore, the correct option is option A.

Additional information:
We have some of the terms related to the spherical mirrors. They are
1. Vertex or midpoint: It is the midpoint in the spherical surface. The object to the vertex is the smallest distance between the mirror and object than the edges.
2. Centre of curvature: On considering the spherical surface as an imaginary sphere, we get a center point that is called the center of curvature. The distance between the center of curvature and all the points in the reflecting surface gives the same length.
3. Principal focus: If we draw the line connecting the vertex and the centre of curvature, the principal focus is the midpoint of the line.
4. Focal length $f$: Distance between the mirror and the principal focus. To find the Focal length, \[\dfrac{1}{f} = \dfrac{1}{{{d_o}}} + \dfrac{1}{{{d_i}}}\].
Where, ${d_o}$=distance between the object from the mirror, ${d_i}$= distance between the image and the mirror.
5. According to the position of the object and image, we can identify the nature of the image
Case 1: When the object is at infinity, a point sized image is formed at the principal focus which is otherwise can be said as behind the mirror. If this is a case, then the image is highly diminished, virtual, and erect.
Case 2: When the object is between the principal axis and infinity which is also behind the mirror but not that much far as infinity. Then the image will be diminished, virtual and erect.

Note:
Since the light is incident on the backside of the convex mirror, it only produces virtual images. Virtual images are formed when the light rays appear to be originating from a point but it is not actually met. Hence the virtual images are always erect. But the real images are always inverted.