Analog electronics (BJT circuit analysis)

[adamaero]

Homework Statement

For beta = 100 and assuming r_o is very large, what is the DC voltage at the collector?

Homework Equations

I_B = I_E(β+1)

I_C = β*I_B

The Attempt at a Solution

Since I_E = 0.5mA, I_B = 0.0505 A
Then, I_C = 5.05 A (which doesn't feel right)
V_C is the same potential across the 30kΩ load?
I tried doing KCL with those currents (to find the current thought the load resistor).
Should I not be analyzing the direct circuit--should I make an equivalent T-model?

 

[Charles Link]

Homework Statement

View attachment 110203
For beta = 100 and assuming r_o is very large, what is the DC voltage at the collector?

Homework Equations

I_B = I_E(β+1)

I_C = β*I_B

The Attempt at a Solution

Since I_E = 0.5mA, I_B = 0.0505 A
Then, I_C = 5.05 A (which doesn't feel right)
V_C is the same potential across the 30kΩ load?
I tried doing KCL with those currents (to find the current thought the load resistor).
Should I not be analyzing the direct circuit--should I make an equivalent T-model?

Your equation should read $I_E=I_B (\beta+1)$. Try again. I think you also need to assume $V_{BE}=.7 \, volts$ (approximately). One hint for you: The capacitors basically block any steady state current trying to go through them so the capacitor is an open circuit for the DC part of the analysis.