Is current density a vector or a scalar? Express its relation with electric field.

Is current density a vector or a scalar quantity ? Deduce the relation between current density and potential difference across a current carrying conductor of length l, area of cross-section A, and number density of free electrons n. How does the current density, in a conductor vary with (a) increases in potential gradient ? (b) increase in temperature? ( c) increase in length? (d) increase in area of cross-section? (Assume that the other factors remain constant in each case).

What is intesity of electromagnetic wave? Give its relation in terms of electric field E and magnetic field B

Is electric current a vector or scalar quantity ? Explain

What is intensityof electromagnetic wave? Give Its relation in terms of electric field E and magnetic field B

Vectors And Scalars

Define electric dipole moment. Is it a scalar or a vector ? Derive the expression for the electric field of a dipole at a point on the equatorial line of the dipole.

a. A steady current flows in a metallic conductor of non - uniform cross section. State which of the quantities i.e., current density, electric field, and drift velocity, current density, electric field, and drift velcoity remain constant? b. A steady current passes through a cylindrical conductor. Is there an electorn field inside the conductor?

Define the term current density of a metallic conductor. Deduce the relation connecting current density (J) and the conductivity (sigma) of the conductor when an electric field E is applied to it.