Answer any

**four**of the following:-
1 (a)
Explain differential amplifier with active load.

5 M

1 (b)
What is cross-over distortion in class B power amplifier? Explain with waveform?

5 M

1 (c)
State advantages of negative feedback on performance of amplifier.

5 M

1 (d)
For the circuit given below calculate dc bias voltages V

_{B1}, V_{B2}and V_{C2}.
5 M

1 (e)
For the circuit given below determine the 3dB frequencies and the bandwidth.

5 M

2
Design a two stage RC coupled amplifier for following requirements:

F

S

V

Select transistor from the table at the end of question paper.

F

_{L}better than 15 Hz. A_{v}≥ 1500S

_{Ic}< 8, R_{i}≥ 1MΩV

_{cc}=6 VSelect transistor from the table at the end of question paper.

20 M

3 (a)
Explain Class B Push Pull amplifier and derive the expression for maximum efficiency.

10 M

3 (b)
For the given differential amplifier determine dc voltages, currents and single ended output voltage V

_{01}.
10 M

4 (a)
For Class B amplifier with V

(i) Maximum input power.

(ii) Maximum output power.

(iii) Maximum circuit efficiency.

(iv) Transistor dissipation.

_{cc}=20V driving an 16Ω, determine:-(i) Maximum input power.

(ii) Maximum output power.

(iii) Maximum circuit efficiency.

(iv) Transistor dissipation.

10 M

4 (b)
Explain high frequency analysis of a BJT amplifier. Derive necessary expressions.

10 M

5 (a)
Draw the circuit diagram of Wein Bridge Oscillator and explain its working. Derive the necessary equation for frequency of oscillations and for sustaining oscillations.

10 M

5 (b)
For the following circuit, determine

A, β, A

A, β, A

_{f}, Z_{if}, Z_{of}, and A_{vf}.
10 M

6 (a)
Determine the lower cut-off frequency for the following network.

10 M

6 (b)
For a current series negative feedback amplifier, derive the expression for the input and output resistances with feedback and comment on the result.

10 M

Write short notes on any

**three**:-
7 (a)
Heat sink and its design steps.

7 M

7 (b)
CMRR improvement in differential amplifier.

7 M

7 (c)
Nyquist stability criterion.

7 M

7 (d)
Crystal Oscillator.

7 M

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