Electrical Engineering Department (NDll)
Course title :Electronics ll
Course code:EEC 214
Solved past question .
Define faithful application.
State the principle of operation of JFET transistors.
Of what advantage is the high input impedance of JFET.
Compare in a tabular for the terminals of FET and BJT.
State 5 advantages of FET.
Use the figure below to answer question f and g.
What is the role of the emitter by pass capacitor CE
Select a suitable value for the emitter by pass capacitor for the circuit above if the amplifier is to operate over a frequency range from 2KHz to 10K
a) Define the following terms and parameter for JFET.
I) AC drain resistance, r
ii) Irans conductance, g
iii) Amplification factor,
(b) State the relationship between the terms in (a) above.
(C) when a reverse gate voltage of 15V is applied to a JFET, the gate current is 10-3. Find the resistance between gate and source.
a) Sketch the output characteristics of a FET transistor indicating the following,
(I) short-gate drain current.
(ii) Pinch off voltage.
(b) Write the expression for the drain current in FET.
(c) A JFET has the following parameters IDSS=32mA, VGS(OFF) =-8V, VGS=-4.5 find the value of the drain current, ID.
(a) State three (3) application of JFET.
(b) State two (2) reasons for transistor biasing.
(c) In a transistor amplifier, when the signal changes by 0.02V the base current change by 10 and collector current by 1mA. If collector load Rc=5K and RD=10K find;
(a) What is Quiescent point?
(b) Define amplification
C(I) State three (3) transistor configuration you know.
(ii) identify the configuration in c(i) above that exhibit all type of gain.
(d) A change in drain voltage of 2V produces a change in drain current of 0.02mA. Find the A.C drain resistance.
(a) Define the following terms;
(i) D.C load line.
(ii) A.C load line.
(b) Draw the circuit of a practical single stage transistor amplifier and explain the function of each component.