Transitor to conduct

[lecto]

One condition required for a transistor to conduct is that the
1. emitter-base junction must be reversed biased.
2. emitter-base junction must be forward biased
3. base-collector junction must be forward biased
4. emitter-collector junction must be reversed biased.

 

[carbonzit]

So what is it?

Were you not paying attention in class that day, and want us to just give you the answer?

What good will that do? Will you understand the concept if we just spoon-feed you?

Or will you go on to become a lousy engineer who builds stuff that doesn't work?

We'll be glad to help you if you ask us what you need help with. But just doing your homework for you? I don't think so.

 

[lecto]

You are an idiot. I have an answer and I"m just double it checking here perhaps you probably do not even know the answer. Ive posted on several other forum and got positive feedback.What do you want me to say 'Hi', 'Hello' I don't long talk! If you have something negative to say just STAY OUT OF MY POSTS!!!!

 

[crutschow]

Don't get snotty.

If you want us to help verify your answer then provide us with it. You gave no indication that you had an answer. You just dumped the question in the post and apparently expected someone to give you an answer. If you can't communicate clearly as to what you want, then you will make a poor engineer.

 

[upand_at_them]

lecto, Why not wire up a transistor (try both NPN and PNP) in the various configurations and find out?

 

[crutschow]

lecto, Why not wire up a transistor (try both NPN and PNP) in the various configurations and find out?

That may give an answer but it doesn't really help in understanding the fundamental operation of the transistor, which I think is the purpose of the question.

 

[KeepItSimpleStupid]

I don't like the way this is going. Although I'm not fond of giving away the answers without a little bit of work.

Here's what I suggest. Take an NPN transistor and draw the conditions for the choices.

Do the same for the PNP transistor.

Now, you have to know what "forward biased" and "reversed biased is". Do you know that? A diode is forward biased when conventional current flows in the direction pointed to by the triangle in the schematic symbol.

There is a "trick" in the problem too and that's the direction mentioned may be unusual.

See what you can do with this information. Another hint. Look at the spec sheet of a typical transistor such as 2n3904 (NPN) and 2n3906 (PNP).

 

[upand_at_them]

That may give an answer but it doesn't really help in understanding the fundamental operation of the transistor, which I think is the purpose of the question.

Sure it does. It's firsthand experience in how the transistor works. It does, however, require the knowledge that KISS pointed out.

 

[crutschow]

Sure it does. It's firsthand experience in how the transistor works. It does, however, require the knowledge that KISS pointed out.

That's my point. Experimenting in that manner gives you a knowledge of how a black box works but no understanding of what is in the box causing the behavior.