Question

5. Consider a dielectric sphere of radius 10 cm and dielectric constant of 1.2 and conductivity of 10 S/m. At time t=0, lightning strike this sphere and deposits a uniform charge of ImC in to the sphere. (a) What is the electric field intensity inside and outside this sphere for t> 0? What is the current density n the sphere? (b) Calculate the change in the electrostatic energy stored in the sphere as the charge diminishes to 1% of its initial value? (c) Determine the electrostatic energy stored in the sphere outside the sphere. Does this energy change with time?