A block of pure silicon at `300 K` has a length of `10 cm` and an area of `1.0 cm^(2)`. A battery of emf `2V` is connected across it. The mobility of electron is `0.14 m^(2) v^(-1) S^(-1)` and their number density is `1.5 xx 10^(16) m^(-3)`. The mobility of holes is `0.05 m^(2) v^(-1) S^(-1)`.
The electron current is

Options

A. `6.72xx10^(-4)A`
B. `6.72xx10^(-5)A`
C. `6.72xx10^(-6)A`
D. `6.72xx10^(-7)A`

Answer

D

Explanation

`E=(V )/(l)=(2V)/(0.1m)=20Vm^(-1)`
`A=1.0cm^(2)=1.0xx10^(-4)m^(2)`
`v_(e)=mu_(e)E=0.14xx20=2.8ms^(-1)`
The electron current is `I_(e)=n_(e)Aev_(e)`
`=(1.5xx10^(16))xx(0.1xx10^(-4))xx(1.6xx10^(-19))xx2.8=6.72xx10^(-7)A`