BJT Biasing - Simple easy 1 minute answer

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    Biasing Bjt
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Discussion Overview

The discussion revolves around the biasing of a BJT (Bipolar Junction Transistor) circuit, specifically focusing on calculating the currents (IB, IC, IE) and voltages (VCE, VBC, VEB) for given parameters. The context is primarily homework-related, involving theoretical calculations based on provided circuit values.

Discussion Character

  • Homework-related, Technical explanation

Main Points Raised

  • One participant questions whether IE is automatically 0 amps given that RE = 0 ohms.
  • Another participant clarifies that a 0 Ω connection from the emitter to ground does not imply that IE is 0 amps.
  • There is a discussion about the validity of the equation IE = IB + IC, with participants confirming its correctness.
  • Participants express uncertainty about how to apply the equation in their calculations.

Areas of Agreement / Disagreement

Participants generally agree that the equation IE = IB + IC is correct, but there is some confusion regarding the implications of RE being 0 ohms on the value of IE.

Contextual Notes

There are unresolved questions about the application of the equation and the implications of the circuit parameters on the calculated values.

ally34
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Homework Statement


Find IB, IC, IE, VCE, VBC, and VEB for the NPN transistor in the circuit below for β = 50, 150, 500. Let VCC = 10 V, R1 = 100 KΩ, R2 = 400 KΩ, RC=2 KΩ, and RE = 0 Ω. Assume VBE = 0.7V.

Homework Equations



V = iR
IE = Ib + Ic

The Attempt at a Solution



My question is that if RE = 0 ohms, then is Ie automatically 0 amps?

But the how does Ie = Ib + Ic apply? Because I got 92.25uA for Ib and 4.56mA for Ic?

Help! :]
 
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Forgot to put the figure :]
 

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ally34 said:
My question is that if RE = 0 ohms, then is Ie automatically 0 amps?
No. A piece of connecting wire from emitter to ground = 0 Ω :smile:
 
NascentOxygen said:
No. A piece of connecting wire from emitter to ground = 0 Ω :smile:


Awwww!

:[ So Ie = Ib + Ic is correct?

I would use this to calculate Ie?
 
ally34 said:
Awwww!

:[ So Ie = Ib + Ic is correct?
Yes.

I would use this to calculate Ie?
It is involved in the calculations.
 

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