Question

Two identical glass rods S₁ and S₂ (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 S₁ 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

(a) 60 cm

(b) 70 cm

(c) 80 cm

(d) 90 cm

Answer 1

at glass rod S₂
1→  n refraction

at glass rod S₁
for n→  1 refraction