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What is meant by Q point?
What is the need for biasing a transistor?
What factors are to be considered for selecting the operating point Q for an amplifier?
Distinguish between d.c and a.c load lines with suitable diagrams.
Briefly explain the reasons for keeping the operating point of a transistor as fixed.
What three factors contribute to thermal instability?
Define ‘Stability Factor’.Why would it seem more reasonable to call this an instability factor?
Draw a fixed bias circuit and derive an expression for the stability factor.
If the coordinates of the operating point of a CE amplifier using fixed bias or base resistor
method of biasing are Vce=6v and Ic=1mA,determine the value of R c and RB.
Derive an expression for the stability factor of a collector –to –base bias circuit.
Mention the disadvantage of collector –to-base bias. Can they be overcome?
Draw a circuit diagram of CE transistor amplifier using emitter biasing .Describe qualitatively the
stability action of the circuit.
Draw a voltage divider bias and derive an expression for its stability factor.
Why does potential divider method of biasing become universal?
Draw a circuit which uses a diode to compensate for changes in ICO .Explain how stabilisation is
achieved in the circuit.
How will you provide temperature compensation for the variations of VBE and stabilization of the
operating point?
If the various parameters of a CE amplifier which uses the self bias method are VCC=12V,R1=10
KΩ,R2=5KΩ,Rc=1KΩ,RE=2KΩ and β=100,find(i)the coordinates of the operating point, and (ii) the
stability factor, assuming the transistor to be silicon.
In a CE germanium transistor amplifier using self bias circuit, RC=2.2K,β=50 ,VCC=9V and the
operating point is required to be set at IC=2mA and VCE =3V.Determine the values of R1,R2,and RE.
Determine the operating point for the circuit of a potential divider bias arrangement with
R2=RC=5KΩ,RE=1KΩ and R1=40KΩ.
Calculate the values of R1 and Rc in the voltage divider bias circuit so that Q-point is at VCE=6V
and IC=2mA.Assume the transistor parameters are α=0985,ICBQ=4µA and VBE=.2V