In a semiconductor the concentrations of electrons and holes are `8xx10^(18)//m^(3)` and `5xx10^(18)//m^(3)` respectively. If the mobilities of electrons and hole are `2.3m^(2)/"volt-sec"` and `0.01m^(2)//"volt-sec"` respectively, then semiconductor is-

Options

A. N- type and its resistivity is `0.34` ohm-metre
B. P-type and its resistivity is `0.034` ohm-metre
C. N-type and its resistivity is `0.034` ohm-metre
D. P-type and its resistivity is `3.40` ohm-metre

Answer

A

Explanation

`n_(e)=8xx10^(18)//m^(3), n_(h)=5xx10^(18)//m^(3)`
as `n_(e)gtn_(h)`, N-type
Conductivity `(sigma)=e(mu_(e)n_(e)+n_(h)mu_(h))`
= `1.6xx10^(-19)[8xx10^(18)xx2.3+5xx10^(18)xx0.01]`
`rho=(1)/(sigma=0.34)Omega-m`.