Hi again dear friends. , hope all are doing well.
Please could some one evaluate my work and advise me in case any correction isrequired.
Have a good day

 

What steps have you taken to check your results?

Which do you expect to have the higher Vbe, the answer to (i) or the answer to (ii)?

 

I think the answer to (ii) sould have higher Vbe since Ic is more

 

See

 

Thanks Bordodynov...
The Vbe voltage is not matching with the values that obtained by me...

So what has gone wrong, I'm wondering.

Can you suggest where is my mistake?

 

i. 25e-3*ln((5e-3/0,98e-13)+1) = 0,6163872887428
exp(Vbe/25mV)-1=5e-3/0,98e-13
exp(Vbe/25mV)=5e-3/0,98e-13+1
Vbe/25mV=ln((5e-3/0,98e-13)+1)= 24,65549154971
24,65549154971*25e-3 = 0,6163872887428
I shall understand with program LTspice, why program gave the value-added result.
ii. if Vce=const=5V ==>
Vbe(9.95mA)=25e-3*ln((9,95e-3/0,98e-13)+1) =0,633590654711
but Vce != 5V Vce=(10V-1000*9.95)=50mV Vbe-Vbc=50mV !
That must be taken into account for the calculation of both terms of the equation
Make the equation. Unfortunately for accurate calculation of the gain "ar" needed.

 

Thank pal for your time
I appreciate you
Please see below
I don't understand the hi lighted once.
Which formula you have used.
Can you explain this for me because I'm confused little bit since they are not according to my formula

 

See

 

I figured out with LTspice.
With regard to my calculations. In the beginning I wrote the final result, and then brought the detailed steps.
Do not pay attention to the second calculation result.
In the case of 9.95 mA compose equation Ebers-Mole. Take as I ar = 0.5 (af = 0.98). Drop unit in parentheses (because of their smallness in comparison with the exhibitors). Add the equation Vbe-Vbc = 50mV. Use the properties of the exponential exp (A-B) = exp (a) * exp (-b)

 

Thanks very much Bordodynov
You are great
Finally I got the correct values
Again I say thank you very much since you paid attention to my thread.
Godby for timbieng.