Question

Which one of the following statement is not correct?

(a) The SI unit of charge is ampere-second.

(b) Debye is the unit of dipole moment.

(c) Resistivity of a wire of length l and area of cross-section A depends upon both I and A.

(d) The kinetic energy of an electron of mass m kilogram and charge e coulomb, when accelerated through a potential difference of V volt is eV joule.

Answer 1

(c) Resistivity of a wire of length l and area of cross-section A depends upon both I and A.

The resistivity of a materials does not depend on its length a thickness but depends on the nature of the substance and temperature. It is a characteristic property of the material of the conductor and varies only if its temperature changes.