• # question_answer Two mirrors, placed perpendicularly form two sides of a vessel filled with water. A light ray is incident on the water surface at an angle$\alpha$and emerges at an angle$\beta$after getting reflected from both the mirrors inside. The relation between$\alpha$and$\beta$is expressed as A)  $\alpha =\beta$ B)  $\alpha >\beta$ C)  $\alpha <\beta$ D)  All are possible depending upon$\alpha$

From above diagram, we have $90-{{\theta }_{1}}+90-\theta +45{}^\circ +90+{{\theta }_{2}}=180{}^\circ$ $\Rightarrow$${{\theta }_{1}}+\theta =45{}^\circ ={{\theta }_{1}}+{{\theta }_{2}}$ $\Rightarrow$${{\theta }_{1}}={{\theta }_{2}}$ $\Rightarrow$$\alpha =\beta$