How to get the blue current?

Ban me or whatever but tell it to me before please.

I've been 30 minutes thinking about it and I have no clue

What a strange looking commutative diagram

What does the blue line represent ?

>>9107283
current going by the 3,3K resistance

nhgfdaf

>>9107268
>Asking about the current of a BJT without stating the current gain

If you ignore the Early effect and Vs << 10V, you can draw the equivalent DC circuit where the capacitors are open circuit (ie. [math] V_s [/math] and [math] R_L [/math] branches are ignored) and the transistor become a controled current source and a diod.

Then you apply the KCL and you can obtain the following system :
[eqn] I_{blue} = \beta I_B = I_S \exp(\frac{V_B}{V_T})[/eqn]
[eqn] V_B = 10 - \frac{I_{s}}{\beta} \; (1.2*10^6)[/eqn]
[eqn] V_C = 10 - I_{s} \; \exp(\frac{V_B}{V_T}) \; (3.3*10^3)[/eqn]

With [math] V_T = \frac{k_B T}{q}[/math] the thermal voltage (26mV @ 300K) and [math]I_s[/math] the saturation current.

Don't forget to check if [math]V_{BC} < 0.4 V [/math] otherwise the transistor is satured and [math]\beta = \beta_{forced}[/math]

Here's one way to do it (but only if all the assumptions hold and you have beta and/or I_s) hope I didn't do any mistake doing my KCL, it's been a few time .