00:01
In this question we have been given that a copper conductor has a diameter of 0 .6 inch and the length is given as 1200 feet.
00:22
Also the total dc current is assumed as 50 ampere.
00:38
We have to find the total resistance, then the current density, then we have to find the dc voltage between the conductor and lastly power.
01:15
So let us start with part a to find the total resistance.
01:24
So for the part a, the total resistance of the conductor can be given by the formula r equals to rho l divided by a, where r is the resistance, rho is the resistivity of the copper, l is the length of the conductor and a is the cross sectional area.
01:48
Substituting the values we will get.
01:49
Let us first find the value of a which is equals to pi multiplied by 0 .6 divided by 2 whole square.
02:02
So this would be equal to 0 .2 width inch square.
02:09
Okay.
02:10
Now this would be equal to 0 .0002 meter square.
02:18
So therefore the value of r would be equal to 1 .68 times 10 to the power minus 8 multiplied by 1, 2 double 0, 1200 times 0 .3048 whole divided by 0 .0002.
02:45
Okay.
02:46
So this would comes out to be 0 .201.
02:51
So this is the solution for part a of our question.
02:54
Moving onwards to the part b of the question where we have to find the current density which is given by j equals to i divided by a.
03:12
Okay.
03:13
So let us substitute the values.
03:16
J would be equal to 50 divided by 0 .0002...