Bangalore University Diploma Instrumentation & Control Engineering SEMICONDUCTOR DEVICES (Course Code EP, EC & IC) 2007 Question paper

Second Semester Diploma (Annual) Examination

E & C BOARD

SEMICONDUCTOR DEVICES

Time :
3 Hours Max. Marks : 100

Note
1. Question No.1 of Section - I is compulsory

2. Answer any six full questions choosing two questions each from Sections - II, III, and IV.

SECTION - I

1. (a) Fill in the blanks with appropriate word / words.

(i) When small amount of ................... impurity is added to pure semiconductor N-type semiconductors are formed.
(ii) The application of proper de voltages to the transistor for its operation is called ...........
(iii) A FET operates on ................. carrier only.
(iv) PIN diode contains 3 semiconductor layer namely P region, N region and .............
(v) Solar cell is ................... device.
(b) List the advantages and disadvantages of IC's.

SECTION - II

2. (a) Differentiate energy level and energy bands.
(b) Describe the insulator, conductor and semiconductor using energy band diagram.
(c) What is meant by intrinsic semiconductor? How P and N type semiconductor are formed? Explain.

3. (a) What is majority and minority carrier?
(b) What is forward and reverse biased PN junction? Explain V-I characteristics with suitable circuit.
(c) Define the following wrt diode.
(i) Break down voltage
(ii) Peak inverse voltage

4. (a) Explain the characteristic of UJT.
(b) Write a note on TRAPATT Diode.
(c) Explain the characteristics of Tunnel Diode.

SECTION - III

5. (a) Explain output characteristic of PNP transistor in CE mode with circuit diagram. Indicate the different region of importance.
(b) Define thermal run away. How it can be prevented in high power transistor?
(c) Name three different transistor configuration.

6. (a) Explain the construction and working of NPN transistor.
(b) What are three methods of biasing transistor?
(c) Define a and b. Derive the relation between them.

7. (a) Explain the construction and working of LASER Diode.
(b) List the advantages and disadvantages of ICs.
(c) Explain the fabrication of capacitor.

SECTION - IV

8. (a) Compare JFET and BJT.
(b) Explain construction and operation of n-channel JFET.
(c) Mention the applications of JFET.

9. (a) Describe the construction and working of depletion type MOSFET.
(b) Define following w.r.t. MOSFET :
(i) Threshold voltage
(ii) Inversion layer
(c) List the advantages of MOSFET over JFET.

10. (a) Define the following :
(i) Photo emissivity
(ii) Photo conductivity
(iii) Photo voltaic effect
(b) Write note on opto coupler
(c) Explain construction and working of Solar cell.