question_answer

Two identical glass rods \[{{S}_{1}}\] and \[{{S}_{2}}\] (refractive index\[=1.5\]) have one convex end of radius of curvature 10 cm. They are placed with the curved surfaces at a distance d as shown in the figure, with their axes (shown by the dashed line) aligned. When a point source of light P is placed inside rod \[{{S}_{1}}\] on its axis at a distance of 50 cm from the curved face, the light rays emanating from it are found to be parallel to the axis inside \[{{S}_{2}}\]. The distance d (in cm) is

Answer:

(70)