I thought that Vcc-Ic.Rc= Vout and Vb=Vcc.700/(700+R2) by thevenin Vcc-Ic.Rc-Vce-Ie.990=0. But the question asks for the Ic and Vout. And i think i have a mistake from the equations above.

 

I thought that Vcc-Ic.Rc= Vou

This equation is OK.

Vb=Vcc.700/(700+R2)

Wrong, not so fast. You forgot about the base current.

https://forum.allaboutcircuits.com/threads/transistor-base.81886/#post-585781

Vcc-Ic.Rc-Vce-Ie.990=0

Looks good .

 

This equation is OK.


Wrong, not so fast. You forgot about the base current.

https://forum.allaboutcircuits.com/threads/transistor-base.81886/#post-585781


Looks good .

If the equation Vcc-Ic.Rc=Vout is correct then how the output voltage changes for different values of R2?
And i couldnt write the correct equation for the Ib.

 

Vcc= 700.I1+ R2.I2
I1=Ib+ I2
I2.R2=Vbe+ Ie.990
I2.R2=Vbe+ Ib.(B+1).990
I can write these equations from your previos link

 

If the equation Vcc-Ic.Rc=Vout is correct then how the output voltage changes for different values of R2?

By changing R2 you change the Vb voltage. Hence the Ib and Vbe will also change. Or we can say that by changing R2 value you change Vth voltage and Rth resistance.

 

By changing R2 you change the Vb voltage. Hence the Ib and Vbe will also change. Or we can say the by changing R2 value you change Vth voltage and Rth resistance.

Yes Vb and Ib are changing so that Vbe is also changing but there is no equation for Vout and Vbe or others. Vout is related with Vcc and Ic. Ohh i understand now. If Ib changes Ic also changes. My mistake! Thank you so much!! By the way i cant say Vcc=700.I1+I2.R2 right? Vcc is only coming from collector or not?

 

Vcc=700.I1+I2.R2 right?

Right.