(adsbygoogle = window.adsbygoogle || []).push({}); 1. The problem statement, all variables and given/known data

I have A transistor Circuit As shown in the figure. I want to find out the current in all branches that is I(b), I(c) and I(e).

2. Relevant equations

As far as I know, the equation I(c) = β * I(b) is only valid when I(b) is less than certain critical value called the saturation current. Above it, I(c) don't increase with I(b) but is constant (as shown in the graph in the figure.) and Is equal to the saturation current given by

I(c) saturation = Vcc / (Rc + Re)

3. The attempt at a solution

I attemted a solution as shown in the figure. I would like to know if it is correct?

If its correct, then One thing is bothering me too much.

If we calculate the voltage across the base and collector terminal, it comes out to be

V(cb) = (Vcc - 1mA * 12K) - (Vcc - 1.4mA * 5K)

= -5V

i.e. Collector base junction is forward biased and 5v is across its terminals. I think for forward bias, the junction acts just like a regular diode, so, a forward voltage of 5V and a reverse current of 1mA is certainly not allowable!! What am I getting wrong?

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# Homework Help: Simple Transistor Circuit

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