10/13/2

Q5. Polarisation charge in a dielectric

Two parallel plates have equal and opposite charges. When the space between the plates

is evacuated, the electric field is E, = 3.20 x 105 V/m.

When the space is filled with dielectric, the electric field is Ea = 2.50 x 105 V/m.

a) What is the dielectric constant?

b) What is the value of the induced or polarisation Electric field?

c) What is the surface charge density produced by this polarization field? Assume the

charge is uniformly distributed on each surface of the dielectric.

d) What is the surface charge density on the capacitor plates?