D7265
Total Pages: 2

Reg No.: Name:

Max. Marks: 100

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b)

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APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
THIRD SEMESTER B.TECH DEGREE EXAMINATION, DECEMBER 2017

Course Code: EC205
Course Name: ELECTRONIC CIRCUITS (EC, AE)

PARTA

Answer any two full questions, each carries 15 marks.
What is the condition for an RC circuit to behave as an integrator?
Design a differentiator circuit to differentiate a square wave of 20V peak to peak
amplitude and 1.5KHz frequency.
Prove that for an emitter follower circuit gain is approximately one.
For a voltage divider network, Ri=36K, ‏بط‎ = 9K, Re =2K, Rc =9K, ४८९८ 24V,
Vpr=0.7V. Calculate Ic and Vcg for B=100.
Derive Input impedance and Voltage gain of a Common Emitter Amplifier with
emitter bypassed for the mid frequency range using hybrid 7 model.
For a fixed bias circuit, Vcc=10V, 1२४ = 50K, २८ = 500Q. Assume silicon transistor
with 9550 and ‏جج۷‎ = 0.7V. Find the co-ordinates of Q point.
A square wave of peak to peak amplitude 4V extending +2V with respect to ground
is applied to a low pass RC circuit. The duration of positive section is 0.2sec and
that of negative section 15 0.1sec. Plot the output waveform. The time constant of the
circuit is 0.2sec.
For the circuit shown, calculate input impedance, output impedance and voltage gain
for the mid frequency range using hybrid 7 model. Rp=6.8K, Rc=4.7K, ൨ =0.99

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GND

PART B

Answer any two full questions, each carries 15 marks.
Draw the circuit diagram of a RC phase shift oscillator and explain its working.
Derive the expression for frequency of oscillation.
Derive expression for short circuit current gain in terms of frequency of operation.
Calculate the bandwidth fg and capacitance ரே of a BJT whose 7 = 50017112 2 =
ImA, B = 100 and Cu = 0.3pF
Explain how negative feedback acts on gain, distortion, stability and frequency
response of a circuit.

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Duration: 3 Hours

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