Question

(a) In tin at room temperature, the mobility of mobile electrons is about 1.5 ✕ 10-3 (m/s)/(V/m), and there are about 3.7 ✕ 1028 mobile electrons per m3. Calculate the conductivity σ. In actual practice, it is usually easier to measure the conductivity σ and deduce the mobility u from this measurement.

Answer 1

The value is
`\sigma = 8.88*10^(6) \ C\cdot m^2 / V \cdot s`

Step-by-step explanation:

From the question we are told that

The mobility of electron in a tiny room is
`\mu = 1.5 *10^(-3) \ (m/s)/(V/m)`

The number of mobile electron per
`m^3` is
`N = 3.7 *10^(28)`

Generally the conductivity is mathematically represented as

`\sigma = N * e * \mu`

Here
`e` is the charge on a single electron and that value is

`e = 1.60 *10^(-19 ) \ C`

So

`\sigma = N * e * \mu`

=>
`\sigma = 3.7 *10^(28 ) * 1.60 *10^(-19) * 1.5 *10^(-3)`

=>
`\sigma = 8.88*10^(6) \ C\cdot m^2 / V \cdot s`