Question

A ray reflected successively from two plane mirrors inclined at a certain angle undergoes a deviation of 300⁰. The number of images observable are

• A. 10
• B. 11
• C. 12
• D. 13

Answer 1

Answer: (B)

11

Answer 2

By using $\delta = ( 360 - 2 \theta ) \Rightarrow 300 = 360 - 2 \theta$

$\Rightarrow \theta = 30 ^ { \circ }$. Hence number of images $= \frac { 360 } { 30 } - 1 = 11$