A copper wire has a resistance of `10 Omega` and an area of cross-section `1 mm^(2)`. A potential difference of `10 V` exists across the wire .Calculate the drift speed of the electrons if the number of electrons per cubic metre in copper is `8 xx 10^(21)` electrons.

Answer

` 0.078mms^(-1)`

Explanation

`I = (V)/(R ) = nA e upsilon_(d) or upsilon_(d) = (V)/(nA eR)`
`upsilon_(d) = (10)/((8 xx 10^(28)) xx 10^(-6) xx(1.6 xx 10^(-19)) xx 10)`
`= 0.078 xx 10^(-3)ms^(-1) = 0.078 "mms"^(-1)`