Solving for Vc, Vb, Ve, Ib, Ic and Ie

[eehelp150]

Homework Statement

Find Vc, Vb, Ve, Ib, Ic, and Ie
Vbe is 0.7V

Homework Equations

KVL

The Attempt at a Solution

Vb = (10*30k)/(80k) = 3.75V
Ve = Vb-Vbe = 3.05V
Ie = Ve/Re = 0.305A
Icmax = 10/(1010) = 9.9mA
Ie is much greater than 9.9mA, so this circuit is saturated. Is this correct?

 

[NascentOxygen]

Vb = (10*30k)/(80k) = 3.75V

This is true iff the base current is zero or negligible.

It is better to apply Thévenin and say V_B = 3.75 – I_B×30k||50k

Q still turns out to be saturated, yes.

 

[rude man]

1. Substitute labels for the resistors, like R1, R2 etc. Substitute actual values only at the end.
2. Write Σi = 0 at the base and emitter junctions. Let Ve = Vb - 0.75V. Gives you 4 independent equations in 4 unknowns.
3. Assume no saturation and solve for ib, Vb, Ve and Vc. If Vc turns out to be < Ve your equations were invalid and you have saturation.