Electronics subject notes for preparation. Adding more points shortly.

1. Subject Title :
Electronics
Prepared by,
Vijay Balu Raskar
Mr. Vijay Balu Raskar
RASKAR
(BE)Electrical Engineer
Electronics is the branch of engineering. Electonics derived
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from Greek word ‘Elektron and Electron Mechanics’
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2. Subject Title : Electronics
Prepared by , Mr. Vijay Balu Raskar vijayraskar2003@yahoo.co.in / vijay.raskar1986@gmail.com
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ELECTRONICS
S. NO NAME OF CHAPTER MARKS
1 Introduction to electronics 04
2 Semiconductor Theory 10
3 Semiconductor Diode 20
4 Rectifiers Filters and Regulators 20
5 Bipolar Junction Transistor 30
6 Field Effect Transistors 10
7 Integrated Circuits 06
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3. Subject Title : Electronics
Prepared by , Mr. Vijay Balu Raskar vijayraskar2003@yahoo.co.in / vijay.raskar1986@gmail.com
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1. Introduction to electronics
Chapter number one is under construction.
Refer other chapters because of importance.
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4. Subject Title : Electronics
Prepared by , Mr. Vijay Balu Raskar vijayraskar2003@yahoo.co.in / vijay.raskar1986@gmail.com
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2. Semiconductor Theory
Q.1 Define semiconductor.
Ans:- The material whose electrical conductivity lies between those of
conductors and insulators and hence negative temperature coefficient
of resistance are known as semiconductors.
Q.2 Write a short note on semiconductor.
Ans:- They are classified as,
There are two types of semiconductor,
1) Intrinsic semiconductor and
2) Extrinsic semiconductor a) P-type and b) N-type
Explanation:-
 The material whose electrical conductivity lies between those of
conductors and insulators and hence negative temperature
coefficient of resistance are known as semiconductors.
 Semiconductors have low conductivity of order of 10 7 s/m.
 They have low resistivity of the order of 10 1 to 10 2 ohm-m.
 There is low forbidden energy gap (Eg = 1eV).
 Resistance of semiconductor material decreases with increase in
temperature.
 They have moderate concentration of free electrons.
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5. Subject Title : Electronics
Prepared by , Mr. Vijay Balu Raskar vijayraskar2003@yahoo.co.in / vijay.raskar1986@gmail.com
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 At room temperature, they act as a moderate conductor of
electricity.
1) Intrinsic Semiconductor:-
 A semiconductor in an extremely pure form is known as
intrinsic semiconductor.
 An intrinsic semiconductor also called an undoped
semiconductor or i-type semiconductor.
 Intrinsic Semiconductor has a negligible conductivity at room
temperature.
 Semiconductor material with larger impurity concentrations
(Example silicon and germanium)
 The current which will flow in an intrinsic semiconductor
consists of both electron and hole current.
 In intrinsic semiconductors the number of
excited electrons and the number of holes are equal: n = p.
Conduction in Intrinsic Semiconductor:-
 Current conduction is takes place by electron and holes.
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6. Subject Title : Electronics
Prepared by , Mr. Vijay Balu Raskar vijayraskar2003@yahoo.co.in / vijay.raskar1986@gmail.com
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 The free electrons are generated due to the breaking up of some
covalent bonds by thermal energy.
 The electron experiences the force towards the positive terminal
of the battery.
 The holes experience the force towards the negative terminal of
the battery.
 Random motion of electrons and holes occur a net movement
called drift.
 This random motion is not contributing to any electric current.
 The free electron drifts towards the positive terminal of the
battery and holes towards the negative.
 This moment of charge carriers constitute the electric current.
 Electron flows from negative to positive terminal of the battery.
 Current flows from positive terminal to negative terminal of the
battery.
 The total current inside the semiconductor crystal is the sum of
electric currents due to the free electrons and holes.
 When the flow of charge carriers is due to an applied voltage the
resultant current is called a drift current.
 Diffusion current is also exit by the difference of carrier
concentration from one region to another.
 The current which will flow in an intrinsic semiconductor
consists of both electron and hole current.
2) Extrinsic Semiconductor:-
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7. Subject Title : Electronics
Prepared by , Mr. Vijay Balu Raskar vijayraskar2003@yahoo.co.in / vijay.raskar1986@gmail.com
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 Electrical conductivity have to be increased by adding a certain
amount of desired impurity atoms to intrinsic semiconductor is
called as extrinsic semiconductor.
 The process of deliberately adding or diffusing impurity atoms to
the intrinsic semiconductor crystal is called doping.

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