Question

We wish to obtain same sized image of an object, using a concave mirror of focal length 15 cm. where should be the object placed from the mirror?

Answer 1

The real and inverted image produced by a concave mirror becomes of equal size to the object when both object and images are situated on the centre of curvature.

The Object is Placed at C

Here the two rays emerging from the object are one parallel to the principal axis and other passing through the focus of the mirror. These rays after reflection from an image at point C. the image formed has the same size as that of the object and it is real and inverted.

Solution

This indicates that the object distance is equal to the radius of curvature for the mirror.

We know that Radius of curvature =2× focal length of the mirror.

From the given data focal length of the mirror =15cm

So, object distance = radius of curvature = 2 x f

=2×15cm

=30cm

Check out the video given below to know more about magnefication

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