Question

A silver wire has a radius of 0.1 cm and carries a current of 2A. The drift velocity of the electron in the silver wire is

We are given: 

Auogaidro’s number = 6.023 x 10²³ 

Atomic weight of silver = 108 

Density of silver 10.5 x 10³ Kg/m³ 

Charge on the electron = 1.6 x 10^-19C

(1) 7 x 10^-4 m/s

(2) 7 x 10^-6 m/s

(3) 7 x 10^-3 m/s

(4) 0.7

Answer 1

(1) 7 x 10^-4 m/s

Since the valence of silver is one so each atom of silver can be assumed to contribute one electron. 

By Avogadro’s law, we have 1g mole of substance = 6.023 x 10²³ atoms 

Hence number of electrons per unit volume will be

Now we know I = nev A where v is the drift velocity.