Question Paper: Electronic Devices and Circuits 1 Question Paper - Dec 17 - Electronics And Telecomm (Semester 3) - Mumbai University (MU)
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## Electronic Devices and Circuits 1 - Dec 17

### Electronics And Telecomm (Semester 3)

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.

Q1) Attempt any five questions

1(a) Explain various types of capacitors
(5 marks) 3663

1(b) Why should collector resistor RC be as large as possible in the design of CE amplifier?
(5 marks) 00

1(c) Explain Zener as voltage regulator.
(5 marks) 2024

1(d) State and explain Miller's Theorem.
(5 marks) 00

1(e) Draw and explain small signal model of a diode.
(5 marks) 00

1(f) Explain the hybrid pi model of BJT.
(5 marks) 3608

2(a) Explain the fabrication steps of passive elements.
(5 marks) 3770

2(b) Explain concept of zero temperature drift in JFET
(5 marks) 00

2(c) Design an L section LC filter with full wave rectifier to meet the following secifications: The DC output voltage $V_{DC} = 220 V$ deliver $IL = (70 \pm20 ) mA$ to the resistive load and the required ripple factor is 0.04
(10 marks) 3528

3(a) Draw small signal hybrid parameter equivalent circuit for CE amplifier and define the same. What are the advantages of h parameters?
(10 marks) 2282

3(b) Determine IDQ, VGSQ, VDSQ if IDSS = 9 mA and Vp=-3 V for the circuit given

(10 marks) 00

4(a) Design the resistors of a single stage CS amplifier for audio frequency with BFW11 with $IDS = (3.3 \pm 0.6) mA$ and $| Av | = 12$.
(10 marks) 00

4(b) For the circuit shown below in Fig.4(b), the transistor parameters are $V_{BE}(on)= 0.7 V, β = 200$ and $V_A= \infty$

• i) Derive the expression for lower cut-off frequency (or time constant) due to input coupling capacitor.
• ii) Determine lower cut-off frequency and midband voltage gain.

(10 marks) 00

5(a) For the circuit using JFET as shown in Fig. 5(a), if $I_{DSS} = 6 mA$, $V_p = - 6 V$, $rd = \infty$, $C_{gd} = 4 pF$, $C_{gs}= 6 pF$, $C_{ds} = 1 pF$,

Determine i) $V_{GSQ}$ , ii) $I_{DQ}$ , iii) $gmo$ , and iv) $gm$.

(10 marks) 00

5(b) For the circuit shown below in Fig. 5(b), the transistor parameters are $V_{BE(on)}= 0.7 V$, $β = 100$ and $V_A = \infty$. Determine $Z_i$ , $Z_O$ and $A_V$.

(10 marks) 00

Q6) Write short notes on: (Attempt any four)

6(a) High frequency r equivalent model of common emitter BJT.
(5 marks) 3608

6(b) Stability factors of various biasing techniques of BJT.
(5 marks) 00

6(c) Comparison of BJT CE and JFET CS amplifier.
(5 marks) 3772

6(d) Different types of filters.
(5 marks) 00

6(e) JFET parameters.
(5 marks) 2279