Question

Which is the only condition under which a concave mirror forms a virtual and upright image on the principal axis?

A when an object is placed at the focal point on the principal axis
B. when an object is placed at the center of curvature on the principal axis
c. when an object is placed between the center of curvature and focal point on the principal axis
D. when an object is placed between the focal point and the vertex of the mirror

Answer 1

The only condition under which a concave mirror forms a virtual and upright image is when an object is placed between the center of curvature and the focal point on the principal axis.

Step-by-step explanation:

Concave or converging mirrors are recessed inward and hence reflect light to an inward focal point. Depending on the distance of the objects from the focal point and the center of curvature of the concave mirror; the image reflects at various positions.

On placing the object between the focal point and the center of curvature of the concave mirror, we get a virtual upright image away from the focal point on the principal axis behind the mirror. In this position we get a larger image.

We can find this image on a ray diagram by tracing the reflected rays backward where they all meet.

Answer 2

D - When an object is placed between the focal point and the vertex of the mirror.

Step-by-step explanation:

When you place an object between focal point and vertex of the mirror then an upright and virtual image will be formed behind the mirror which will be larger than the original size of the object. Here's how:

Step 1: Please refer to the schematic 1:

In this schematic, we have a principal axis, a concave mirror, center of curvature, focal point, vertex of the mirror.

Step 2: Please refer to the schematic 2:

In this schematic, I have placed the object between the focal point and the vertex of the mirror.

Step 3: Please refer to the schematic 3:

In this attachment, I have tried to show you when the light rays are emerged on the object and how they reflect back and form an upright and virtual image behind the mirror which is larger than the object itself.

Let us consider, two particular incident rays which are passing through the object. One is passing through center of curvature to the object till the mirror and reflect back as it is. And another one which is passing through the object and then coincides at vertex of the mirror and reflect back at an angle. Those two reflected rays will never meet as they are divergent rays but when we extrapolate these reflected rays on the opposite side they will meet and form an upright and virtual image behind the mirror.

Thus, definitely the correct answer is D.