Recent questions tagged transistor

Description : Compare P.N.P and N.P.N transistor.

Last Answer : Parameter PNP transistor NPN transistor Definition Two blocks of p- types semiconductors are separated by one thin block of n-type semiconductor. Transistor in which two ntype layer ... Positive Voltage  Emitter Terminal Collector Terminal Ground Signal High Low

Description : Draw construction of SCR using two transistor model. Explain its operation.

Last Answer : Two Transistor Model of SCR or Thyristor

Description : Draw the V-I characteristics of power transistor. 

Last Answer : V-I characteristics of power transistor:

Description : Describe thermal runaway of transistor and explain how it can be avoided.

Last Answer : Concept of thermal runaway:  1.We know that  IC = β IB + (1+ β) ICO  Where ICO is the leakage current and ICO is strongly dependent on temperature. 2. Leakage current approximately doubles for ...   Thermal runaway can be avoided by : 1) Using stabilization circuitry 2) Heat sink 

Description : Define α and β of the transistor. 

Last Answer : α: The ratio of collector current IC to emitter current IE for a constant collector to base voltage VCB in the CB configuration is called current gain alpha (α).   β : The ratio of collector ... a constant collector to emitter voltage VCE in the CE configuration is called current gain beta (β) .

Description : List various transistor biasing methods.

Last Answer : Types of biasing methods: i. Base bias (or fixed bias) ii. Base bias with emitter feedback. iii. Base bias with collector feedback iv. Voltage divider bias (or self bias) v. Emitter bias. 

Description : Transistor operating configurations

Last Answer : Transistor operating configurations

Description : Define junction field effect transistor (JFET) and give an example.

Last Answer : Junction Field-Effect Transistor: It is a semiconductor device having three terminals, namely Gate, Drain and Source, in which the current flow is controlled by an electric field set up by an external voltage applied ... : i) n-channel JFET and ii) p-channel JFET Examples of JFET: BFW 10, BFW 11 

Description : Explain working of n-p-n transistor in unbiased condition.

Last Answer : Construction of NPN transistor: For an unbiased transistor no external power supplies are connected to it. Base is sandwiched between collector & emitter terminal. It is thin & lightly doped ... providing external power supply to transistor & this process is known as Biasing.

Description : Define α & β and derive the relation between (α) &) (β) of transistor.

Last Answer : α : The ratio of output collector current IC to input emitter current IE in the CB configuration is called current gain alpha (α).  β : The ratio of output collector current IC to the input base current IB in the CE configuration is ... ( 1/β) + 1  hence 1/ α = (1+β )/ β  Therefore, α = β /(1+β)

Description : Define biasing of transistor

Last Answer : Biasing of transistor is the process that makes the base emitter junction of transistor always forward biased and collector junction reverse biased for achieving the faithful amplification .

Description : With neat diagram explain working of NPN transistor.

Last Answer : N-p-n transistor is made by sandwiching thin layer of p-type semiconductor between two layers of n-type semiconductor. It has three terminals - Emitter, Base and collector. The npn transistor has two ... up in the collector as it is more positive. In this way, current flows in the transistor.

Description : Draw and explain self-basing of a transistor.

Last Answer : Transistor Biasing is the process of setting a transistors DC operating voltage or current conditions to the correct level so that any AC input signal can be amplified correctly by the transistor. ExplanationIt ... Applying KVL to o/p loop , Collector-emitter voltage, VCE = VCC − IC RC

Description : Compare between CB , CE & CC transistor configuration.

Last Answer : Parameter CB CE CC I/P impedance Low Or 50Ω Medium Or 600Ωto 4kΩ High Or 1 MΩ Current Gain Less than or equal to 1 High Highest Voltage Gain Medium Medium Less ... k Ω to 50 k Ω Low Or 50 Ω Phase shift between input and output 0° 360° 0° 

Description : Why transistor is called as bipolar device.

Last Answer : BJT is called bipolar device because in BJT current conduction takes place due to majority as well as minority charge carriers that is because of electrons as well as holes.

Description : What is the main use of a transistor?

Last Answer : Main use of a transistor as amplifier and as switch.