# Basic npn bjt problem

1. Nov 13, 2017

### dennislam

1. The problem statement, all variables and given/known data

2. Relevant equations
KVL

3. The attempt at a solution
Using KVL around BE loop
0-0.6-i_e*(30*10^3)-15=0
i_e=-0.52mA
However, I stuck when I tried to find i_c and use KVL around CE loop/ CB loop
For CE loop:
10-i_c*(15*10^3)-Vce-i_e*(30*10^3)-15=0
For CB loop:
10-i_c*(15*10^3)-Vcb=0
I got confused about how to relate Vce and Vcb. (here I guess it must be some kind of relationship that looks like Vbc-Vac=Vba)
Also, it seems like it is operating in cutoff mode (both Vc and Ve>Vb), however, there is current flowing around the loop. So what is the mode that the transistor is actually operating in?
Thank you!

2. Nov 13, 2017

### CWatters

Circuit looks odd to me. Like common base configuration but the polarity of the emitter bias voltage is wrong ( should be -15v). Think the transistor is either off or they made a mistake?

Otherwise I would suggest you assume Ic=Ie.

3. Nov 13, 2017

### Staff: Mentor

Yes, try reversing the polarity of the 15v supply.