In Hall effect measurements ina sodium conductor the strength of a transervse field was found to be equla to `E = 5.0 mu V//cm` with a current density `j = 200 A//cm^(2)` and magentic induction `B = 1.00 T`. Find the conentrations of the condiction electrons and its ratio to the total number of atoms in the given conductor.

Explanation

Here, `v_(d) = (E)/(B)` and `j = "ne" v_(4)`
so, `n = (jB)/(eE) = (200xx10^(4) (A)/(m^(2)) xx 1 T)/(1.6xx10^(-19)C xx 5xx10^(-4)) V//m`
`= 2.5xx10^(28) per m^(3) = 2.5xx10^(22)` per `c.c.`
Atomic weight of `Na` being 23 and its density = 1, motar volume is `23 c.c.` This number of atoms per unit volume is `(6xx10^(23))/(23) = 2.6xx10^(22)` per `c.c`.
Thus there is alomost one conduction electron per atom.