1
GATE EE 1992
Subjective
+5
-0
For the $$JFET$$ amplifier shown in figure $$\mu = 100,\,{r_d} = 50k\Omega $$
$$(i)$$ Draw the $$AC$$ equivalent circuit
$$(ii)$$ Find the voltage gain of the amp
$$(i)$$ Draw the $$AC$$ equivalent circuit
$$(ii)$$ Find the voltage gain of the amp
2
GATE EE 1991
Subjective
+5
-0
Figure shows a common emitter amplifier
$$(a)$$ Simplify the circuit by applying thevenin's theorem to biasing network $${R_1},{R_2}$$ at
$$\,\,\,\,\,\,\,$$ the base of the transistor.
$$(b)$$ Assuming $${C_s}$$ to be a short for frequency range considered. Draw the small signal
$$\,\,\,\,\,\,\,$$ $$a.c.$$ model of the circuit obtained in $$(a)$$ by using the simple model for the
$$\,\,\,\,\,\,\,$$ transistor shown in figure.
$$(c)$$ Evaluate the small signal gain $$\left( {{{{V_0}} \over {{V_i}}}} \right)$$ of the amplifier.
Questions Asked from Small Signal Modeling (Marks 5)
Number in Brackets after Paper Indicates No. of Questions
GATE EE Subjects
Electric Circuits
Electromagnetic Fields
Signals and Systems
Electrical Machines
Engineering Mathematics
General Aptitude
Power System Analysis
Electrical and Electronics Measurement
Analog Electronics
Control Systems
Power Electronics