Drift speed of electrons, when 1.5 A of current flows in a copper wire of cross setion 5 `mm^(2)` , is v. If the electron density in copper is `9xx10^(28)//m^(3)` the value of v in `mm//s` close to (Take charge of electron to be `=1.6xx10^(-19)C)`

Answer

B

Explanation

`I=n e A V_(d)`
`v_(d)=I/(n e A)=1.5/((9xx10^(28))(1.6xx10^(-19))(5xx10^(-6)))=0.02xx10^(-3)m//s=0.02mm//s`