Electronics - Bipolar Junction Transistors (BJT) - Discussion
Discussion Forum : Bipolar Junction Transistors (BJT) - General Questions (Q.No. 12)
12.
The Q point on a load line may be used to determine:
Discussion:
24 comments Page 2 of 3.
Imran said:
1 decade ago
Hey guys answer is right. Vb means not base voltage it means biasing voltage. With the help of load line analysis we find the value of biasing voltage for maintain Ic at Q point. T.
Md.adil said:
1 decade ago
I think answer is wrong it should be Q(vce, ic).
Diptendu Mitra said:
1 decade ago
Vcc-IcRc-Vc=0 [Vc=Vce+Ve+Ground voltage].
or, Vcc-IcRc-(Vce+Ve+0)=0.[since,Vce=Vc-Ve & '0' is Ground voltage].
or, Vcc-IcRc-Vce-Ve=0.
or, Vcc-IcRc-Vce-Vb+Vbe=0 [Vb=Vbe+Ve, or,Ve=Vb-Vbe].
or, (Vcc-IcRc-Vce+Vbe)-Vb=0.
or, Vb=Vcc-IcRc-Vce+Vbe [Vbe=0.7v(approx),Vce=0.2v(approx)].
Now if Vce becomes equal or almost equal to Vbe , Vb=Vcc-IcRc.
So bottom line It could depend on Vb in a way.
or, Vcc-IcRc-(Vce+Ve+0)=0.[since,Vce=Vc-Ve & '0' is Ground voltage].
or, Vcc-IcRc-Vce-Ve=0.
or, Vcc-IcRc-Vce-Vb+Vbe=0 [Vb=Vbe+Ve, or,Ve=Vb-Vbe].
or, (Vcc-IcRc-Vce+Vbe)-Vb=0.
or, Vb=Vcc-IcRc-Vce+Vbe [Vbe=0.7v(approx),Vce=0.2v(approx)].
Now if Vce becomes equal or almost equal to Vbe , Vb=Vcc-IcRc.
So bottom line It could depend on Vb in a way.
Saroj kumar mekap said:
1 decade ago
In CE configuration the general equation is:
Vce = Vcc - IcRc - IeRe.
So there is no relation to Vb. So the answer is Vc.
Vce = Vcc - IcRc - IeRe.
So there is no relation to Vb. So the answer is Vc.
Harpal singh said:
1 decade ago
A load line is used to get quesent point which is Q(Vce,Ice).so in quetion ans. D is correct.............
DIGVIJAY PANDEY said:
1 decade ago
Vc=Vcc-IcRc. SO CURRENT OPTION IS A
Rohit dang said:
1 decade ago
For CE,
Q point signifies the conditions for bjt to be operated in either active cutoff or saturation regions.
And from commonly used diagrams.
Vce=Vcc-IcRc. And this is also the equation of load line in output characterstics (Ic vs. Vce).
Hence from q-point Vce, Ic can be obtained graphically.
But we can also find Vb from relation Vce+Veb+Vbc=0.
Q point signifies the conditions for bjt to be operated in either active cutoff or saturation regions.
And from commonly used diagrams.
Vce=Vcc-IcRc. And this is also the equation of load line in output characterstics (Ic vs. Vce).
Hence from q-point Vce, Ic can be obtained graphically.
But we can also find Vb from relation Vce+Veb+Vbc=0.
Amit gupta said:
1 decade ago
@Satya.
Vb is the base voltage and IcRc is voltage across collector. So there is no relation of Vb in this formula Vce = Vcc-IcRc.
Vb is the base voltage and IcRc is voltage across collector. So there is no relation of Vb in this formula Vce = Vcc-IcRc.
Satya said:
1 decade ago
Krisna Mohan is right
Sukhpreet said:
1 decade ago
@ Mr. krishn mohan
Vce= Vcc-IcRc not Vb = Vcc-IcRc
Vce= Vcc-IcRc not Vb = Vcc-IcRc
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers