1.why the dielectric constant of an insulator can never be infinite whereas that of a conductor is infinite?(plz also tell me the physical significance of dielectric constant)

 

2.a positively charged rod is brought near an uncharged conductor.if the rod is then suddenly withdrawn the charge left on the conductor will be

a-positive   b-zero   c-negative    d-none

(answer is b)

(plz tell me why the answer is not c)

 

3.which among the following is a sure test of electrification?

a-attraction    b-induction    c-repulsion   d-conduction

(answer is c)

 

4.when a positively charged conductor is earth connected

a-electrons flow from conductor to earth

b-no charge flow occurs

c-protons flow from conductor to earth

d-electrons flow from earth to conductor

(answer is b)

(plz tell me why the answer is not c and also tell me exactly what is earthing)