Find the current produced at room temperature in a pure germanium plate of area `2 xx 10^(-4) m^(2)` and of thickness `1.2 xx 10^(-3) m` when a potential of `5 V` is applied across the faces. Concentration of carries in germanium at room temperature is `1.6 xx 10^(6)` per cubic metre. The mobilities of electrons and holes are `0.4 m^(2) V^(-1) s^(-1)` and `0.2 m^(2) V^(-1) s^(-1)` respectively. The heat energy generated in the plate in `100` second is.

Options

A. `2.4 xx 10^(-11) J`
B. `3.4xx 10^(-11) J`
C. `5.4 xx 10^(-11) J`
D. `6.4 xx 10^(-11) J`

Answer

D

Explanation

`n_(e)=n_(h)=n_(i)`
`:. sigma = n_(i)e(mu_(e)+mu_(h)) = 1.6 xx 1.6 xx 0.6 xx10^(-13)`
Current produced in germanium plate.
`I=JA = sigma E.A = sigma((V)/(d))A`
Here generated in the plate, `H = V xx I xx t`
`= 5xx1.28 xx10^(-13)xx100 =6.4 xx10^(-11)` joule.