(b) A capacitor is made of three layers A-B-A insulators in parallel. It is known that the capacitor is a round shape with diameter of 50 mm. An electric field E= 9.3 x 10^
V/m is applied to store charge of 25 x 10" C on each plate. By knowing that the
material A has the dielectric constant of 2.3 and the layers distance of A is 4.3 mm
and B is 2.8 mm, determine the dielectric constant of B.
(8 marks)