The contribution in the total current flowing through a semiconductor due to electrons and holes are `3/4` and `1/4` respectively. If the drift velocity of electrons is `5/2` times that of holes at this temperature, then the ratio of concentration of electrons and holes is

Options

A. `6:5`
B. `5:6`
C. `3:2`
D. `2:3`

Answer

A

Explanation

As we know current density `J=nqv`
`implies J_(e)=n_(e)qv_(e)` and `J_(h)=n_(h)qv_(h)`
`implies (J_(e))/(J_(h))=(n_(e))/(n_(h))xx(v_(e))/(v_(h)) implies (3//4)/(1//4)=(n_(e))/(n_(h))xx5/20 implies (n_(e))/(n_(h))=6/5`