Question

If instead of defining principal axis as the line joining the center of curvature to mid-point of the spherical mirror, if we were to define it as the line shown below, the position of image formed for an object would change.

• A. Always true
• B. Always false
• C. May be true for some special cases
• D. Data insufficient to answer the question

Answer 1

The correct option is B Always false

Got you with the wordplay. Think from 1st principles now, by changing the definition of principle axis, are we in any way changing the physical reality? No, right! So, yup, now it seems obvious, there will be no change in the image formed. Imagine;all the infinite rays that were falling on the mirror and getting reflected to form the image will still do that in the same manner as we didn't change anything with the mirror or the object. So for the image to change, we have to move the object or the mirror, not an imaginary line.