What is the conductivity of a semiconductor (in `Omega^(-1) m^(-1)`) if electron density `= 5 xx 10^(12) cm^(-3)` and hole density `= 8 xx 10^(13) cm^(-3)`?
`(mu_(e) = 2.3 V^(-1) s^(-1)m^(2), mu_(h) = 0.01 m^(2) V^(-1) s^(-1))`

Options

A. 5.634
B. 1.968
C. 3.421
D. 8.964

Answer

B

Explanation

Here, `mu_(e)=2.3m^(2)V^(-1)s^(-1)`
`mu_(h)=0.01m^(2)V^(-1)s^(-1), n_(e)=5xx10^(12)//cm^(3)=5xx10^(18)//m^(3)`
`n_(h)=8xx10^(13)//cm^(3)=8xx10^(19)//m^(3)`
`sigma=e(n_(e)mu_(e)+n_(h)mu_(h))`
`=1.6xx10^(-19)[(5xx10^(18))xx2.3+(8xx10^(19))xx0.01]`
`=1.6xx10^(-1)[11.5+0.8]=1.968Omega^(-1)m^(-1)`