Question Paper: Electronic Devices and Circuits 2 Question Paper - May 18 - Electronics Engineering (Semester 4) - Mumbai University (MU)
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## Electronic Devices and Circuits 2 - May 18

### Electronics Engineering (Semester 4)

Total marks: 80
Total time: 3 Hours
INSTRUCTIONS
(1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Draw neat diagrams wherever necessary.

1.Attempt any four of the following:

1.a. Draw general frequency response of an amplifier. Determine corner frequencies for the following.

(5 marks) 00

(5 marks) 00

1.c. List the steps taken by 8086 processor in response to receiving an interrupt.

$\theta$ $f_C$ = $1.5^o$ C/W , $\theta$ cs = $1^o$ C/W , $\theta_C$A = $50^o$ C/W

$\theta$ JA = $4^o$ C/W , $T_j max$ = $100^o$ C and TAmb = $25^o$ C

(5 marks) 00

1.d. State and Explain barkhausen criteria.
(5 marks) 00

1.e. Explain working of SCR. Define IL and IH.
(5 marks) 00

2.a. Determine voltage gain, i/p and o/p impedance for the two stage amplifier shown below.

(10 marks) 00

2.b. Explain working of RC phase shift oscillator. Give expression for frequency of oscillations.
(10 marks) 00

3.a. Draw block diagram of voltage series negative feedback. Derive formula for $A_{vf}$, $R_{if}$, $R_{of}$.
(10 marks) 00

3.b. Explain working of UJT with the help of characteristics. Hence explain relaxation oscillator.
(10 marks) 00

4.a Determine $I_{DQ}$ , $V_{GSQ}$ and differential mode gain for following circuit.Assume $K_n$ = 0.15 $mA/v^2$ (VA) = 100V VT = 1.5 V.

(10 marks) 00

4.b. Draw circuit diagram of class A Transformer coupled amplifier. Explain working, Draw AC/DC load line. Derive expression of efficiency.
(10 marks) 00

5.a. Explain high frequency response of CS-MOSFET amplifier with proper equation. Discuss effects of parasitic capacitances.
(10 marks) 00

5.b. Explain use of constant current source in diff amps. Give description of any one type.
(10 marks) 00

6. Write short notes on: [ANY THREE]

6.a. Cascode Amplifier working
(7 marks) 00

6.b. Gunn diode and its applications
(7 marks) 00

6.c. Crossover distortion and methods to remove in class B amplifier
(7 marks) 00

6.d. Hartley oscillator.
(6 marks) 00