00:01
The number density of free electrons in the given conductor is 8 .5 into 10 tish per 28 electrons per meter cube.
00:14
Electric field applied across its terminals is 0 .060 newton per coul at the temperature of 20 .0 degrees celsius.
00:29
There is no use of temperature just to make an idea about the resistivity of the copper at this much temperature.
00:40
And this resistivity at this much temperature can be found to be 1 .72 into 10 dashper minus 8 oom into meter.
00:54
Now, in the first part of the problem, we have to find drift velocity of the electrons.
01:01
For which we use an expression for the current density in terms of electric field that is given as j is equal to the ratio of electric field applied to the resistivity of the conductor and another expression is j is equal to current density means current passing through unit area now the relation for the current in terms of drift velocity is i is equal to n e a, vd, where n is the number density of electrons, e, charge over one electron, and vd is the drift velocity here.
01:41
Area will be cancelled out.
01:44
So, j is equal to n, e, vd.
01:48
So using that, using these two equations, we conclude that e by row is equal to n, e into vd.
01:58
Hence, we get an expression for drift velocity, which is given as e, by n, e into row.
02:09
So plugging in all known values, vd, here comes out to be 0 .06 for electric field applied...