00:01
So in this question, you are given a doubt, and you are asking to look at the voltage, which, a reverse voltage, so that the current reaches about 90%, so 90 % of the saturation current, which i denoted by a i -0, at a temperature 27 degrees, which of course is the same as 300, kavans, right? so you know that the current of a doubt depends on the voltage in such a way, the saturation kind of n -0, and the exponential of kvv, v over kbt minus 1.
00:49
So q is the charge.
00:50
In this case, is a electron charge, right? so kb is a broadsman constant, t is the temperature, and v is the voltage.
00:57
So if you, you can plot it to have some idea what this is.
01:02
So voltage is here and the current is here, and it passes zero at zero, right? and it increases as you increase, but actually if you do reverse, it would go like this.
01:11
Okay.
01:12
And the saturation current will be something like here, minus i note.
01:17
Okay.
01:18
As a point, the question is, what would the voltage so that what would the voltage be, let's say somewhere here, so that this is about 90 % of i not, right? so you just need to put this to be 9 %, right? so in other words, if this is an, this is about 9 % that is, you know, it's actually, it should be a minus 90 % okay, to be failed.
01:51
So that actually eqv over kbt, should be just about 10%, right? so this should be about 10%.
02:05
And what you need to do is you take the logarithm of this.
02:08
You get log 10%, right? 10 % that should be equals this qv over kbt, right? log 10 % that is 0 .1, right? so it's point of worm.
02:30
Yeah, that's 10 to minus 1.
02:32
So you can rewrite it as minus log...