Question

A light ray incident on one of mirrors of a pair of mirrors. After fourth reflection, ray starts to retrace its path then which of the following is correct?

• A. Deviation produced by pair of mirrors is ${340}^o$
• B. In this ray diagrma, no. of images formed is 19
• C. for the ray diagram, no. of images formed is 18
• D. for the ray diagram, X $={60}^o$

Answer 1

The correct option is D for the ray diagram, X $={60}^o$

Apply geometry and laws of reflections. The ray that retraces its path should be normal to mirror. X$={90}^0-{30}^0={60}^0$