conductivity derivation and SI unit

Define thermal conductivity. Give its S.I. unit and dimensional formula.

(a) Define the term 'conductivity' of a metallic wire. Write its SI unit. (b) Using the concept of free electrons in a conductor, derive the expression for the conductivity of a wire in te'rms of number density and relaxation time. Hence obtain the relation between current density and the applied electric field E.

The current density in a wire is 10A//cm^(2) and the electric field in the wire is 5 V/cm. If p = resistivity of material, sigma = conductivity of the material then (in SI unit)

Using the S.I. units of torque and angular acceleration show that the S.I. unit of moment of inertia is kg m2

Value of R in SI units is

Derive a relationship between S.I. and C.G.S. unit of work.

Derive an expression for the force between two long parallel current carrying conductors. Use this expression to define SI unit of current.

Ohm is the SI unit of

What are the derived units?

The SI unit of work or energy is joule. Explain why the work and energy have same SI unit.