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sherrellbc
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Homework Statement
The Attempt at a Solution
The impedance in question(Rib) is defined to be, exactly like Rin or any other impedance at a point:
Rb = Vb/Ib
I took the approach of first finding Ib. I did this by using the Beta value given and the emitter current. Using the relationship: Ib = Ie/(beta+1) = 10mA/131 = 76.24μA. Using Ib you can find Vb by making use of the fact that current is drawn into the base of the transistor for PNP devices. Vb = V2 - Ib*Rb = 736.6mV.
Thus, Rib = Vb/Ib = 0.7366V/76.24uA = 9649Ω
This solution is incorrect.
How would one find Rin?
Can someone more clearly explain to me the concept impedances at different part of the circuit? By this I mean, the impedance looking into a certain part of the circuit. I thought of it as the impedance at a certain point, if you will. As in, if you were to somehow 'see', or 'enter,' the base of this transistor, you would encounter Rib impedance. Maybe someone else can explain this concept better to me. I somewhat visualize this concept as one that must be defined by Ohm's Law. As such, if one measures the voltage at a given points as well as the associated current, then there must be a resistance seen by that point.
Thank you.
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