Already have an account? Get multiple benefits of using own account!
Login in your account..!
Remember me
Don't have an account? Create your account in less than a minutes,
Forgot password? how can I recover my password now!
Enter right registered email to receive password!
Explain junction transistors (npn and pnp).
Junction Transistor:
This transistor consists of two p-n junctions combined in one crystal as demonstrated in figure below.
There are two major forms of junction transistors depending on whether the middle section is on a p material or an n material. The middle sector is termed as the base and the outer regions are termed as the emitter and the collector correspondingly.
The transistor is a 3-terminal device and its properties may be given in terms of characteristic curves involving the three currents and the three voltages demonstrated in figure below.
Within a transistor there is zero resultant current of electrons and holes across all junctions. If the collector is connected directly to the base and a small positive voltage is applied among emitter and base after that a current flows just as in a p-n junction diode in the forward direction. Likewise if the emitter is joined to the base and a negative voltage is applied in between collector and base, current flows in the reverse direction, demonstrating a saturation of collector current.
These voltages with similar polarity are applied simultaneously as demonstrated in figure below.
The potential barrier in between base and emitter is decreased and the flow of holes across the barrier greatly rises. There is an increased flow of electrons from base to emitter but because the hole density in the p- region is much higher than the electron density in the n- area, the current may be seem to be mainly because of the holes. The holes enter the n- region and diffuse by this, and combine with the electrons in that area as the base region is made sufficiently thin, many of holes reach the collector and base junction and very little arrive at the base terminal. Holes fall easily into the collector region on account of field at the collector base junction. Therefore the collector current is very nearly equivalent to the emitter current and the base current is almost zero. VCB has little effect on the current as long as its magnitude is above various minimum values and the base is adequately thin. A small change in VEB causes a change in IC resulting in an approximately equal change in IC.
what is a button cells and how is it used on a low current electronic circuit
Q. Show Applications for Synchronous Motors? With constant-speed operation, power factor control, and high operating efficiency, three-phase synchronous motors are employed in
calculation of series DC motor
Q. A 10-kW, 230-V shunt generator, with an armature-circuit resistance of 0.1 and a field- circuit resistance of 230 , delivers full load at rated voltage and 1000 r/min. If the
For Parity Flag CPRE (Call on parity even) and CPO (Call or parity Odd) Instruction CPE calls the subroutine from the specified memory location if parity flag is
Q. Explain the working principle of a d.c. generator. Explain clearly the function of commutator in d.c. machines. Sol. Working principle of a D.C. generator: For the 2- po
Solve using data from the DC machine data sheet, using the "hot" resistance value for all calculations. Note that the value of K on the sheet is for rated (100%) field flux. Assum
What is Logic Gates? The Logic Gates are circuits made up of transistors, diodes, and resistors. The Logic gates process one or more input signals in a logical fashion. Dependin
Calculate the current flow in 30Ω resistor for the circuit in figure using Thevenin's Theorem.
how does it work explain with figure?
Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!
whatsapp: +91-977-207-8620
Phone: +91-977-207-8620
Email: [email protected]
All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd