Asilver wire 2.6 mm in diameter transfers a charge of 420 cin 80 min. silver contains 5.8 x 10^{28} free electrons per cubic meter.
what is the current in the wire?
what is the magnitude of the drift velocity of the electronsin the wire?

1) Current in the wire: 0.0875 A

The current in the wire is given by:

where

Q is the charge passing a given point in the conductor

t is the time elapsed

In this problem, we have

Q = 420 C is the total charge passing through a given point in a time of

t = 80 min = 4800 s

So, the current is

2) Drift velocity of the electrons:

The drift velocity of the electrons in the wire is given by:

where

I = 0.0875 A is the current

is the number of free electrons per cubic meter

A is the cross-sectional area

is the charge of one electron

The radius of the wire is

So the cross-sectional area is

So, the drift velocity is