Answer any one question from Q1 and Q2

1 (a)
Draw h-parameter models for C

_{E}, C_{B}and C_{C}transistor configurations.
6 M

1 (b)
For the circuit shown in Fig 1. Silicon transistor with β=100 is used. Calculate I

_{B}, ,I_{C}and V_{CE}.

6 M

2 (a)
For the circuit shown in Fig 1. Silicon transistor with h

_{ie}=1.1 KΩ, h_{fe}=50, h_{re}=2.5×10^{-4}, h_{oe}=25 μA/V is used. Calculate A_{i}, A_{v}, R_{i}, R_{i}', R_{0}and R_{0}'.
6 M

Answer any one question from Q3 and Q4

3 (a)
Draw and explain Hartley oscillator using BJT. Calculate frequency of oscillation, when C=0.001 μF, L

_{1}=L_{2}=100 μH and mutual inductance between L_{1}and L_{2}is 20 μH.
6 M

3 (b)
Derive the expression for lower cut-off frequency and higher cut-off frequency in terms of percentage tilt and rise time respectively.

6 M

4 (a)
Determine the input resistance of a series input connection and the output resistance of a shunt output connection for an ideal feedback voltage amplifier in which A

_{v}=10^{5}and A_{of}=50. Assume that input and output resistances of the basic amplifier are R_{i}=10 KΩ and R_{0}=20 KΩ respectively.
6 M

4 (b)
Explain the effect of internal capacitance of transistor used in amplifier circuit on bandwidth of amplifier with frequency response curve. Define F

_{α}and F_{β}separately.
6 M

Answer any one question from Q5 and Q6

5 (a)
Draw class B push pull power amplifier and show that
Maximum efficiency is 78.5%.

6 M

5 (b)
A transformer coupled class A power amplifier draws a current of 200 mA from a collector supply of 10 V when no signal is applied to it. Determine:

i) Maximum output power

ii) Maximum collector efficiency iii) Power rating of the transistors. If the load connected across transformer. Secondary is of 2Ω and transformer turns ratio is 5:1.

i) Maximum output power

ii) Maximum collector efficiency iii) Power rating of the transistors. If the load connected across transformer. Secondary is of 2Ω and transformer turns ratio is 5:1.

7 M

6 (a)
Explain with circuit diagram, how even harmonics are eliminated in class B push-pull power amplifier.

6 M

6 (b)
A sinusoidal signal V

_{S}=1.75 sin (600 t) is fed to a power amplifier. The resulting output current is I_{0}=15 sin 600 t + 1.5 sin 1200 t+1.2 ssin 1800 t + 0.5 sin 2400 t. Calculate the percentage increase in the power due to distortion.
7 M

Answer any one question from Q7 and Q8

7 (a)
Explain various non-ideal current voltage characteristics of EMOSFET.

6 M

7 (b)
For the circuit shown in Fig 2. the MOSFET parameters are V

_{T}=3V, k=0.4 mA/V^{2}. Determine V_{GS}, V_{DS}and I_{D}and show that MOSFET is biased in the saturation region:

7 M

8 (a)
For the circuit shown in the Fig 2, determine g

_{m}, A_{D}, R_{i}, R_{i}', R_{0}and R_{0}'. Given V_{T}=3V, k=0.4 mA/V^{2}and r_{0}=40 KΩ.
7 M

8 (b)
Describe Bi-CMOS technology of MOSFET with circuit diagram.

6 M

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