Twenty identical spheres (with equal radius) are arranged, touching one another consecutively, in a complete circular fashion. Now, a uniform point-source (say 'P')of radiation is located at the centre 'O' of the regular polygonal-plane obtained by joining the centres of all the spheres.
What will be fraction of the total radiation intercepted by all the spheres?
Note: Above figure shows circular arrangement of 'n' identical spheres. This picture has been given only for clarification.