What is the Correct Calculation for Transistor Configurations?

[go2255]

This is the result from a lab,but I am not sure the results are correct.

I guess the combination of R1=10k and R2=10k is under linear region,but how come the calculated Ib is zero.

For combination of R1=10k and R2=1k,Idon't know why the Ie is negative.Negative value means error?Is it the cut off mode?

And for combination of R1=1k and R2=10k,it should be in saturation?
I guess either the measured or calculated result is wrong.What is the problem?

Also,there are many differences(highlighted).Is my calculation wrong?

 

[mfb]

How did you get the formulas for I_C and I_E? One of them is wrong, but as there is no explanation where they come from and what you did there it is hard to tell which one.

 

[rude man]

Just to give you general guidance, your results should be
Vb = R1/(R1+R2)10V
Ve = Vb - 0.7V
Ie = Ve/Re
Ib ~ 0
Ic ~ Ie
Vc = 10V - Ic*Rc
Vrc = 10V - Vc

EXCEPT for R1 = 1K, R2 = 10K. For this configuration the transistor is saturated and the computation is more laborious. If you want to attempt it, assume Vc = Ve, write 2 equations in unknowns Ib and Ve. Vb is still Ve + 0.7V.