00:02
Alright, so in this problem for part a, we have a nichrome wire.
00:09
So the temperature coefficient for nichrome is r5 .0 .004 per celsius degrees, okay? so, and we also know that at two different temperatures, one, it is 11 .5 degrees, the total resistance is 100 oms.
00:37
So we want to find out the temperature if the, we want to find a resistance if the temperature is zero.
00:49
So basically we just have r equal, so the initial, so suppose this is r0, okay, r will be equal to r0 times 1 plus alpha times the temperature change.
01:05
So temperature change from 11 .5 to 0.
01:08
So that is negative 11 .5 celsius degrees, right? and r0 here equal 100 oms.
01:16
And rfi is given right here.
01:18
So you can plug in all the values.
01:19
And you see that this value is 99 .54 oms, okay? and in part b, so in this case we'll have a carbon wire...