00:01
Good afternoon, everyone.
00:03
So today we're going to work through a problem where we're asked to determine the current in a given wire where there are this number of electrons passing in a given second in one direction, and the number of protons passing in the other direction.
00:17
Now, the total current is only dependent on the absolute value of the charge.
00:23
So let's go ahead and write that out as an equation.
00:25
Remember, current is a amount of charge that passes a given point in a given amount of time.
00:31
Labeled this as i is equal to the absolute value of the total charge q divided by the change in time.
00:42
Now the problem states that our change in time that these electrons and protons all pass this point in one second, which means we can take this delta t and push it to one.
00:55
All right? so with that being said, we can also rewrite this cue as the number of protons plus the number of electrons multiplied by the elementary charge particle e, which is the charge of an electron, which we have written over here as 1 .6 times 10 to the negative 19th.
01:16
The number of protons that given the problem is 1 .2 times 10 to the 16th, and the number of electrons is 3 .8 times 10 to the 16th.
01:25
Okay, so going back down here, we're ready to solve our problem.
01:29
The total current in the wire is simply going to be equal to i is equal to np which is 1 .2 times 10 to the 16th plus 3 .8 times 10 to the 16th all multiplied by e where e is equal to 1 .6 times 10 to the negative 19.
01:58
Now when we calculate this all out when we add this together and multiply by 1 .6 you're going to get that i is equal to a approximately 0 .008 1 amps...