Second Semester Diploma (Annual) Examination, 2007

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.

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