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)`

Options

A. 2
B. 0.02
C. 3
D. 0.2

Explanation

`I=neAV_d, v_d=I/(neA)=1.5/((9 times 10^28)(1.6 times 10^-19) (5 times 10^16))=0.02 times 10^-3 m//s=0.02 mm//s`