-
The drift velocity of electrons, in silicon—
-
- Is proportional to the electric field for all values of electric field
- Is independent of the electric field
- Increases at low values of the electric field and decreases at high values of electric field
- Increases linearly with electric field at low values of electric field and gradually saturates at higher values of electric field
Correct Option: D
As we know drift velocity, vd = E µn
where vd = drift velocity
E = applied electric field
µn = mobility of electron.
However, with the increase in applied field, the number of electrons in the conduction band increases continuously due to which there will be large number of collision, due to this the motion becomes erratic and linear relationship becomes invalid.
But for E > 104 v/cm, µn is inversely proportional to E.
This means at very high electric field velocity of electron becomes saturate.
Hence alternative (D) is the correct answer.
