Energy from a point source spreads out isotropically in all directions.
A point source radiates energy at the rate of 10 Joules per second, or 10 Watts. As shown in the diagram, two spherical shells of radii r1 and r2 (r1 < r2) receive energies E1 and E2 per second, respectively. Which of the following option(s) is/are true?
A bulb of power 100 W that radiates light isotropically(equally in all directions) has dimensions so small compared to the distances in question that the source can be assumed to be a point source.
Find the intensity 10 m away from it?