Question

The nature of the image formed by the concave mirror when the object is placed at centre of curvature is
A) Real, erect and of the same size.
B) Real, erect and of enlarged size.
C) Real, inverted and of diminished size.
D) Real, inverted and of same size.

Answer 1

Hint: The concave mirror can form both real and virtual images based on the position of object. The size of the image also depends on the position of the image. We can draw a ray diagram to see the nature of the image formed when the object is at centre of curvature. Real images are always inverted and virtual images are always erect.

Complete answer:
The concave mirror forms an image due to convergence of light falling on it due to which it is also known as converging mirror. In a concave mirror the ray parallel to the axis when fall on the mirror it reflects back and passes through the focus while the ray passing through the focus after falling on the mirror reflects and gets parallel to the principal axis. Hence, when an object is placed at the centre of curvature the ray diagram can be given as shown below

Where O is the object, I is the image, C is the centre of curvature and F is the focus. The axis on which the focus and centre of curvature lies is the principal axis.
From the diagram we can see that the image is real, inverted and of the same size.

Hence, the correct option is D.

Note: The images which are formed in front of the mirror are the real image while the image formed behind the mirror are virtual images. In the above case the image is formed in front of the mirror therefore it is real. We will get a real, inverted and diminished size image if the object is placed beyond centre of curvature or at infinity.