Question

state position ,nature and size when object placed at distance equal to focal length in convex mirror

Answer 1

Answer:

position of image : - at focus

size of image : - diminished to a point

nature of image : - virtual and upright

Explanation:

assume an object AB is placed in front of a convex mirror . A ray of light AD incident on the mirror parallal to the principal axis after reflection appears to diverge from focus F along DA₁ . The other ray AE passing towards the centre of curvature C , after reflection retraces it's path EA ( i.e. it gets reflected back along EA ). The two reflected rays DA₁ and EA do not actually meet , but they appear to meet at 'A' behind the mirror when they are produced backwards . Thus A' is the virtual image of the point A . In a similar way taking rays incident from the other points of the object A'B' is the image of AB.

[This explanation is based on the image given here by me]