# A circuit problem

1. Aug 13, 2009

### migelo

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Hi all. I'm new in this forum. and i thought to say welcome with a problem what makes me crazy. It is a pnp-common bjt transistor. made of silicon. the emittor current, the collector current and the base current are asked in the condition of Vin=0V. (alfa=0,98) However when the teacher wrote the kirchoff's rule for the emittor circuit and the collector circuit, he wrote:

for the emittor circuit:
Vee-Veb-(1-alfa)Ie*50-49*Ie=0
he took 0,6 for the Veb cause it is silicon. it is ok. and from here Iee comes out 0,002A.

but for the collector circuit:
Vcc-Vcb-1,98Ic+0,1=0
how 0,1 can be here? there is Ib*Rb. right? we had found 0,002A for the Ie. and when put it in the Ie=Ic+Ib equation, and use the Ic=alfa*Ie, we found 0,00004A for the Ib. and if we multiply it with Rc; 50ohm, we found 0,002A. so where is the +0,1?

we asked the confusing to the teacher, however he didn't give us a saturating reply. so i thooght to ask it to you. i will be waiting for your answers.

and also, i generally need a text book which has got plenty of example problems. (especially about transistors) could you give me some suggestions?

Last edited: Aug 13, 2009
2. Aug 13, 2009

### migelo

http://img41.imageshack.us/img41/9358/circuitw.jpg [Broken]
sorry, i forgot the circuit picture. here it is.

Last edited by a moderator: May 4, 2017