A potential difference of `2V` is applied between the opposite faces of a `Ge` crystal plate of area `1 cm^(2)` and thickness `0.5 mm`. If the concentration of electrons in `Ge` is `2xx10^(19)//m^(3)` and mobilities of electrons and holes are `0.36(m^(2))/(vol t-sec)` and `0.14 (m^(2))/(vol t-sec)` respectively, then the current flowing through the plate will be

Options

A. `0.25 A`
B. `0.45 A`
C. `0.56 A`
D. `0.64 A`

Answer

D

Explanation

`sigma=en_(e)mu_(e)`
`=2xx10^(19)xx1.6xx10^(-19)(0.36+0.14)=1.6(Omega-m)^(-1)`
`R=sigmal/A=l/(sigmaA)=(0.5xx10^(-3))/(1.6xx10^(-4))=25/8 Omega`
`:. i=V/R=2/(25//8)=16/25 A =0.64 A`