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From: Cursitor Doom <cd@notformail.com>
Newsgroups: sci.electronics.design
Subject: Re: kids these days
Date: Mon, 30 Sep 2024 16:46:48 +0100
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On Mon, 30 Sep 2024 08:24:38 -0700, john larkin <JL@gct.com> wrote:

>On Mon, 30 Sep 2024 11:13:56 +0100, Cursitor Doom <cd@notformail.com>
>wrote:
>
>>On Mon, 30 Sep 2024 05:15:02 GMT, Jan Panteltje <alien@comet.invalid>
>>wrote:
>>
>>>On a sunny day (Sun, 29 Sep 2024 10:36:26 -0700) it happened john larkin
>>><JL@gct.com> wrote in <kb3jfjpejs47hqjd00fis20eog8de19ae8@4ax.com>:
>>>
>>>>I wouldn't hire someone who complicates a simple question into
>>>>paralysis.
>>>>
>>>>
>>>>I draw a 10 volt battery connected to two resistors, 9K in series with 1K.
>>>
>>>The problem there is 'draw', no reality.
>>>The battery will have an internal resistance, maybe discharged too.
>>>
>>>>What's the voltage across the 1K?
>>>
>>>
>>>
>>>>I hired a 3-month intern a month ago who failed the test. He said 9
>>>>volts. I hired him anyway and fired him as an intern on Friday. He's
>>>>full time now. He's mostly a software engineer. I'm teaching him basic
>>>>electronics now. 
>>>
>>>Well, that is OK.
>>>But needs experimenting, building circuits, else all vaporware.
>>>Same with software, write it, test it, else just imagination...
>>>It may not be / work for everybody..
>>>Some run for US precedent..
>>>When I have to believe the crap trump puts out these days (about Iran for example)
>>>4 sure (or maybe even 00 sure <where 00 is the symbol for infinite> ) we will have
>>>WW3 no matter who is winning the electtions.
>>>
>>>
>>>>I dream of some day finding a kid who gets the voltage divider right
>>>>and has something intelligent so say about the next test, an NPN
>>>>emitter follower. 
>>>
>>>Ge or Si?
>>
>>John mentioned a Vb of 0.6V so the 'student' is expected to know it's
>>silicon. And of course, it's a Vbe of 0.6V and that distinction seems
>>to trip up a lot of young folks, it seems. The Vb is 5. Once they get
>>that straight, the rest of it falls into place easily enough. Should
>>take < 30s for someone to figure out - and hopefully <<!
>
>No, I said that one EE grad claimed that Vb (not Vbe) would be 0.6
>volts to ground.
>
>Can anyone here say about what the base and emitter voltages actually
>are? Collector current?
>
>+10 supply, two 10Ks making a divider into the base, 1K emitter to
>ground, typical small silicon NPN.
>
>Extra credit: anything else to say?

Seriously? Vb is 5V. Vbe is 0.6V so Ve is 4.4V which gives us an Ie of
4.4/1000 = 4.4mA. Ic will be slightly less obviously but to a first
approximation we usually take them to be the same. Vc = 10V.
I don't see how anyone can get tripped up by this.