00:01
Okay, so we have a gavanometer that requires a current of 1 .5 millie -ampere to have a full -scale deflection.
00:15
So this problem says we can use this to measure a bigger current, for example, this of one ampere.
00:24
Because but if we use another resistor okay in parallel because most of the current so we are going to get most of the current go through here and only the 1 .5 milanpher come to the gubernamer okay so actually you can see that this current is the total current and let's go i which is the one coming through here minus the one coming to the galvanometer.
00:59
Okay, so the question is, what is it the value of this resistor? okay, so we want to find this r.
01:08
Okay, so in this case we are going to use kirchukov rules, okay, and more specifically we are using the loop rule.
01:20
This says that the sum of all the potential differences across a close loop equals zero okay so i'm using my loop like obviously the loop that contains both of the resistors and i'm something like this okay in that sense if you do it otherwise it's the same and the only thing that changes are designs okay but it's just the same so for the first part i have actually the potential difference in the galvanometer.
02:00
Remember that by omnslaw, this is the value of the internal resistor times the current...