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`
`rArr J_(e)=n_(e)qv_(e) and J_(h)=n_(h)qv_(h)`
`or (J_(e))/(J_(h))=(n_(e))/(n_(h)) xx (v_(e))/(v_(h)) rArr (3//4)/(1//4)=(n_(e))/(n_(h))xx(5)/(2)`
`rArr (n_(e))/(n_(h))=(6)/(5)`