Question

A real object is moving towards a fixed spherical mirror. The image:
A. Must move away from the mirror.
B. May move towards the mirror.
C. May move towards the mirror if the mirror is concave.
D. Must move toward the mirror if the mirror is convex.

Answer 1

Hint: There are two common types of the spherical mirrors of a real object at different locations in front of the Spherical mirror. Since generally we have studied that there are two kinds of spherical mirror-(i) Concave mirror and (ii) Convex mirror. So, to get the correct answer we have to go through with the concept behind the image formations of a real object in each case separately.

Complete step by step solution:
Case (I) For concave mirror: As we know that as the object is facing near toward the concave mirror the image formed will be real until the position of the object reaches a location that lies in between focus and the pole of the mirror. In this scenario, the image formed by the concave mirror is inverted and the size of the image will decrease gradually as we move the object towards the fixed mirror. While when we place the object in between the pole and the focus of the mirror. The image will be virtual, enlarged, and formed behind the mirror.

Position of object ($u$)	Position of image($v$)	Nature and size of the image
1. At infinity	At the focus	Real and Highly diminished.
2. Beyond the center of curvature	Between the pole and the focus	Real, inverted, and diminished
3. At the center of the curvature	At the center of the curvature	Real, inverted, and equal to the size of the object
4. Between the pole and the focus	Beyond the center of curvature	Real, inverted, and Enlarged
5. At focus	At infinity	Real, inverted and Highly Enlarged
6. Within focus (between focus and the pole)	Behind the mirror	Virtual, erected and enlarged.

Case (II) For convex mirror: In the case of convex mirror image of the object will always be virtual, smaller/diminished and lies in-between the pole and the focus.

Position of object ($u$)	Position of image($v$)	Nature and size of the image
1. At infinity	Behind the mirror at the focus	Virtual, erected and highly diminished
2. Anywhere between pole and infinity.	Behind the mirror in between focus and pole.	Virtual, erect and diminished

$\therefore$ It is not also mentioned that the nature of the image formed by the spherical mirror is real or virtual. So On analyzing both the cases carefully we can say that Option (B),(C), and (D) are correct.

Note:
In order to tackle these kinds of problems, we should have a fundamental knowledge of image formation by both concave and convex mirror. To grasp the concept behind the given problem one should have to practice a lot of conceptual questions on the topic of the principle of image formation by the spherical mirror.