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

Conductivity `(sigma)="ne"(mu_(e)+mu_(h))`
= `2xx10^(19)xx1.6xx10^(-19)(0.36+0.14)=1.6(Omegam)^(-1)`
`R=rho(l)/(A)=(l)/(sigmaA)=(0.5xx10^(-3))/(1.6xx10^(-4))=(25)/(8)Omega`
`i=(V)/(R)=(2)/(25//8)=(16)/(25)=0.64` A .