Answer to Question #218293 in Electricity and Magnetism for Anita

Question

If = nabla . D = epsilon nabla . E and nabla . J = sigma nabla . E in a given material, the material is said to be

(a) Linear

(b) Homogeneous

(c) Isotropic

(d) Linear and homogeneous

(e) Linear and isotropic

(f) Isotropic and homogeneous

Answer 1

Gives

$\nabla.D=\epsilon_0\nabla .E$

$\nabla.J=\sigma\nabla. E$

Linear :-

D(r,t)=constant$\times E(r,t)$

Both eqution follow linear property

Homogeneous :-

$D(E)$ does not depend r

J(E) does not depend r

Isotropic :-

D(E) independent of direction it E

J(E) in depending direction E

But J and E depending direction of E

Isotropic statement not follow

Option (d) is correct