# NPN BJT Transistor Circuit Analysis Problem: Is This Question Solvable?

I've been doing some circuit analysis questions as practice but came across one that seemed very odd:

As far as I can tell, this question is missing information and therefore unsolvable? I was able to find Iload since I had all the information needed there. However, I am unable to find RB simply because I'm missing V (voltage for the base). As there are two unknowns there, the problem cannot be solved. Am I correct in this judgement, or am I not seeing something?

Thanks.

• You are given Vbe.
– JRE
Commented Oct 16, 2018 at 6:19
• It is possible that the problem allows you to choose both $V$ and $R_\text{B}$? (I think their value for $V_\text{BE}$ is really the value for $V_{\text{BE}_\text{SAT}}$. So you know the base voltage (relative to ground), by definition.) $\beta_\text{SAT}$ isn't specified. But you may be allowed a reasonable guess for that, as well. But who knows?
– jonk
Commented Oct 16, 2018 at 6:19
• i don't think there is enough information. and $V_{BE} = 0.95$ V seems awful high. Commented Oct 16, 2018 at 6:45
• The voltage measurements indicate the Collector voltage is well below the Base voltage, thus the transistor is operating in Saturation. You know the Base voltage, so derive a formula that depends on the unknown Vin. Commented Oct 17, 2018 at 6:31