Describe the a transistor at explain it's working ? || what is p-n-p transistor || define n-p-n transistors || explain transistor || inter important physics questions

 

Describe the a transistor at explain it's working ?

Ans:- Transistor means transfer of resistance.

*** These are discovered John Borden , W.H. Brattain , william shackles in 1948. Transistor as three terminals.

1) Emitter :- The left portion of the Transistor is called Emitter.
** It is made up of high doped semiconductor. It Intermediate size.

2) Base :- The middle part of the Transistor is called Base.
** It is made up of lightly doped semiconductor. It is smaller in size.

3) Collector :- The right portion of the Transistor is called Collector.
** It is made up of moderately doped semiconductor. It is larger in size.

Transistors are two types :-
a) p-n-p Transistor :-
b) n-p-n Transistor:-

a) working of p-n-p Transistor :-

*** In p-n-p transistor emitter and collector made up of P type and base made of n type semiconductor.

*** In these emitter base junction is forward baise and base collector is reverse baise.

*** The holes present the emitter are repelled by positive terminal of the emitter battery croses emitter junction these causes emitter current ( Ie ).

*** Remaining holes crosses collector junction enter into collector region.

*** These holes are attracted by negative terminal of the collector battery.

*** Each holes lost in the battery one elections in release from the battery it gives collector current ( Ic ).

Ie = Ib + Ic

Symbol :- 

b) Working of n-p-n Transistor :-

 

*** In n-p-n transistor emitter and collector made up of n type and base made of P type semiconductor.

*** In these emitter base junction is forward baise and base collectors is reverse baise.

*** Electrons present in the emitter are strongly repelled by negative terminally emitter battery crosses emitter junction it gives emitter current ( Ie ).

*** A few electrons combines it holes present in the base it will gives base current ( Ib ).

*** Remaining elections crosses collector junction enter into region.

*** These electrons are strongly attracted by positive terminal of the Collector battery it gives collector current ( Ic ).

Ie = Ib + Ic

Symbol :-