The Figure shows the equatorial circle of a glass sphere of radius R having centre at C. The eye of an observer is located in the plane of the circle at a distance R from the surface. A small insect is crawling along the equatorial circle.
(a) Calculate the length (L) of the are on the circle where the insect lies where its image is visible to the observer.
(b) Calculate the value of L when the eye is brought very close to the sphere. Refractive index of the glass is `mu =(1)/(sqrt(2))`

Answer

(a) `(piR)/(3)` (b) `piR`