To find the index error

PHYSICS · Multi-part · CBSE · Physics · Ray Optics and Optical Instruments · Ray Optics and Optical Instruments

Problem

e

, the distance between the object needle and the pole of a concave mirror is

20\ \text{cm}

. The separation between the indices of the object needle and mirror is observed to be

20.2\ \text{cm}

. In an observation, the observed image distance is

20.2\ \text{cm}

and the observed object distance is

30.2\ \text{cm}

. Find: (a) The index error

e

. (b) The focal length of the mirror

f