Question

If current is decreased then drift velocity decreases?

Answer 1

Well, yes...

Explanation:

As long as the cross-sectional surface area, charge on the particles, and the charge-carrier density stay constant then yes.

`I=nAqv`, where:

• `I` = current (`A`)
• `n` = charge carrier density (number of charge carriers per unit volume) (`m^-3`)
• `A` = cross sectional surface area (`m^2`)
• `q` = charge on the individual particles (`C`)
• `v` = drift velocity (`ms^-1`)

As I said earlier, if `n`, `A`, and `q` stay constant, then `Iproptov`, so as current decreases, drift velocity decreases,

Another way to think of it, `I=(DeltaQ)/(Deltat)` which means how many coulombs of charge pass through per second, or how many electrons pass through per second. If the number of electrons passing through per second decreases, then the electrons must be travelling slower, and so have a smaller drift velocity.