a) i) Derive boundary conditions at the interface between two different charge free dielectric media. ii) Derive a formula relating angle of the fields and the normal of the boundary and the relative permittivity's of the two media. (12 marks) b) i) Given that D-4a, 3ay + 6a, in a medium with 13. X-0 is the boundary and the other medium has &2 5. Find D. ii) Verify the formula derived in a (ii) for the example b (i). (8 marks)