Maharashtra State Board of Technical Education 2008 Diploma Electronics and Communication Industrial Electronics - Question Paper

Subject: Industrial Electronics
Third Year: Semester 5
3 Hours / 80 Marks
November 2008



Instructions:
1) All ques. are compulsory
2) Illustrate your answers with neat sketches wherever necessary
3) Figures to the right shows full marks
4) Assume suitable data, if needed

1. Attempt any 4 of the following: [Marks: 16]

a) Draw the symbols of :
i) LASCR
ii) GTO
iii) Diac
iv) SBS

b) Draw the V-I characteristics of SCR and define its regions.
c) Define turn-On time for SCR. List 2 turn-On methods of thyristor.
d) Compare single phase and 3 phase rectifier.
e) Give the function of free wheeling diode in controlled rectifier with neat sketch.
f) Draw the structure of UJT and PUT.

2. Attempt any 2 of the following: [Marks: 12]

a) With neat circuit diagram discuss the working of single phase full wave controller rectifier with resistive load. Draw its waveforms.
b) Explain the working of UJT triggering for SCR with circuit diagram. Draw its waveform.
c) Describe 3 phase half wave rectifier with circuit diagram and waveforms.

3. Attempt any 2 of the following: [Marks: 12]

a) What is commutation? Draw and discuss class-c communication with related waveforms.
b) Explain the working of these of 3 phase full wave rectifier with circuit diagram. Draw its waveforms.
c) Draw the circuit diagram of single phase half wave controller rectifier with indicative load. discuss its working and draw its waveforms.

4. Attempt any 2 of the following: [Marks: 16]

a) Draw and discuss the circuit diagram of single phase half controlled bridge rectifier with resistive load. Draw its waveform.
b) Explain R and RC triggering circuit for SCR with circuit diagram and waveforms.
c) Draw and discuss the structure of SCR and 2 transistor analogy of SCR.

5. Attempt any 2 of the following: [Marks: 12]

a) Draw the circuit diagram and discuss the working of single phase full controller rectifier with inductive load. Draw its waveforms.
b) Draw the V-I characteristics of TRAIC and define 4 operating modes of TRIAC.
c) Draw the V-I characteristics of power transistor and define its regions.

6. Attempt any 2 of the following: [Marks: 12]

a) Explain the working of single phase full controller bridge rectifier with an inductive load. Draw its waveforms.
b) Describe the constructional details of IGBT with neat sketch. Draw V-I characteristics of it.
c) Draw and discuss class-D communication with necessary waveforms.

Earning:   Approval pending.