00:01
This question, we have copper wire of radius small r equals to 0 .0250 centimeter, that is, 0 .0250 multiplied by 10 to the power minus 2 meter.
00:13
And the length of the wire capital l is equal to 3 .00 meter and resistivity row equals to 1 .72, multiplied by 10 to the power minus 8 oom meter.
00:28
And the current sorry the density of charge carriers is small n equals to 8 .50 multiplied by 10 to the power 28 electrons per meter cube okay so for the part a of the problem in which we have to determine the resistance of the copper wire and which is given by r equals to row l by a where capital a is the area so area will be pi r square so now substituting all the values in this equation we get r equals to is 1 .7 to multiplied by 10 to the power minus 8, multiplied by 3 divided by pi multiplied by r.
01:07
R is this value, okay? so 0 .0 -250, sorry for the mistake, 0 .0 -250 multiplied by 10 to the power minus 2 square.
01:18
Okay.
01:19
So from here after solving, we get resistance r equals to 0 .263 home.
01:24
Okay, so this is the answer for the part a of the problem.
01:28
Moving to the part b in which we have to determine the potential difference across the copper wire.
01:36
So from the oms law, we can write delta v equals to ir...