If the current in a specific copper wire increases this can be due to _____________________.

The conductance of a conductor of resistance 2 milli ohm

The average relaxation time during collision of electrons with atoms is

The dimensional formula of current density is

n e V_{d = ____ ?}

Current density formula is

Directions of drift velocity of electrons and electric field are

A conductor of cross-sectional area 0.10  $mm^2$  carries a current of 2.5 A. If the number of conduction electrons per cubic metre is  $1.0\times10^{28\ }$   $m^{-3}$  . What is the value of drift velocity of the free electrons in the conductor?

 A conductor of length 2.0 m and cross-sectional area 5.0 $\times10^{-6}\ m^2$  carries a current of 6.0 A. If the drift velocity of the conduction electrons is 1.5 $\times10^{-4}\ m\ s^{-1}$ , what is the number of electrons in the conductor?

A tungsten wire of length 1.00 m and cross-sectional area 2.01 $\times10^{-6}\ m^2$  carries a current of 5.00 A. If the number of free electrons per unit volume is 4.3 $\times10^{28}$  , what is the time taken by an electron to travel from one end of the wire to the other end?

There are 6.23 $\times10^{24}$  free electrons per  $cm^3$  in a wire. The average drift velocity of the electrons is 1.1 $\times10^{-3}m\ s^{-1}$ . Calculate the current density in the wire.

A current flows in a copper wire. The current density in the wire is 1.4 $\times10^6A\ m^{-2}$ . If the number of free electrons in 1 $m^3$  of wire is 8.4 $\times10^{28}$ , what is the drift velocity of the electrons? 

A charge of 60 Coulomb flows in a wire for 45 minutes. If the diameter of the wire is 1.0 mm, what is the current density in the wire?

The conductivity of copper is 6.0  $\times10^7\Omega^{-1}m^{-1}.$  The free electron density copper is 8.45 $\times10^{28}m^{-3}$  . Estimate the mean time between collisions of free electrons and positive ions in copper.