Question

F. What is the transistor? Why transistor use in electrical circuit? Design a problem of the following circuit t help other students better understand transistors. Make sure you use reasonable number 15 pts

explain each step

Answer 1

Transistor:

A transistor is semiconductor device. It consist of three terminals (Base, Emitter and collector). There are different types of transistors like, Bipolar Junction Transistor (BJT), JFET, MOSFET,etc.There are two types of bipolar juction transistors,

(i)NPN transistor

(ii)PNP transistor

The transistor is a current controlled device. Beacause the output voltage depends on input current.

Uses of transistor:

1. Transistor is used as amplifier to amplify the weak signals

2.Transistor is used as Electric Switch.

Given Crocuit R2 A Transistor Symbol RI WL Vc + is B E 10 R .NPN DE PNP It is collector to Base bias circuit. The purpose of biasing is to fix a constant de collector current isrespective of variations of B , temperature, leakage corent, ete The Circuit (an be drawn as follows fe RI Au & CIBTIC) Tric -13 R3 & ТЕ Apply KVL to input loop - V + (IBtic). R2 & IB RAVBE +IE RZ=0 V = [R2 + R3] IF & IBRI TUBE I EIBTIC V = [R2 t23] CIts) IB IIB. RIT BE =(1+ß). IB.

To [ 482483)CHB) tri] = Vi - VBE IB - V-VBE RI + (R21 23 ) CI+B) Ic B V-BE R1 + R2 t) (148) Ic = VI-VIBE (R21 R2) TR B (1) P CR2tR3) RI B Ic a VI-VBE (R₂ R3) "Ic' is independent of B.