State the working principle of LED and LASER diode.

State the working principle of LED and LASER diode.
by

1 Answer

Answer :

LED 

Working principle of LED diode:An LED emits two light when electrical energy is applied to it.LED is a two terminal device.The terminals are named as anode (A) and the other as cathode(K). A PN junction is formed between the anode and cathode.So LED is basically a PN junction diode. For proper operation,it is necessary to forward bias the LED as shown in fig and symbol of LED is also shown.This shows that the symbol is same as that of a PN junction diode with two arrows indicating that it emits light.

image


LASER

Working principle of LASER diode:There are three main processes in semiconductors that are associated with light:

1) Light absorption

2) Spontaneous emission

3) Stimulated emission

image

image

by

Related questions

Describe the working principle of Laser Diode.

Description : Describe the working principle of Laser Diode.

Last Answer : When the P-N junction of a laser diode is forward-biased by an external voltage source, electrons move across the junction and recombination occurs in the depletion region which results in the ... point, a strong beam of laser light comes out of the partially reflective surface of the diode.

Describe the operating principle of LASER diode with diagram.

Description : Describe the operating principle of LASER diode with diagram.

Last Answer : Operating Principle: There are three main processes in semiconductors that are associated with light: Light absorption Spontaneous emission Stimulated emission Stimulated emission is ... LASER special properties such as narrow spectral width and coherent output radiation. 

Describe working principle of LASER.

Description : Describe working principle of LASER.

Last Answer : There are three main processes in semiconductors that are associated with light: 1. Light absorption 2. Spontaneous emission 3. Stimulated emission Stimulated emission ... emission which gives LASER special properties such as narrow spectral width and coherent output radiation

Describe the working principle of LED with neat construction.

Description : Describe the working principle of LED with neat construction.

Last Answer : Working Diagram Working:-When the junction is forward - biased the electron in the n-region combines with the holes. These free electrons reside in the conduction band and at the ... . While returning back, the recombining electrons give away the excess energy in the form of light

Draw symbol and state one application of zener diode and LED.

Description : Draw symbol and state one application of zener diode and LED.

Last Answer : Diagram: Application of Zener diode:  It is used as voltage regulator. Used in protection circuits for MOSFET. Used in pulse amplifier. Used in clipping circuits. ... alarm systems 7-segment, 16- segment and dot matrix displays Indicating power ON/OFF conditions

List applications of Schottky diode and Laser diode.

Description : List applications of Schottky diode and Laser diode.

Last Answer : Application of Schottky diode:  It is used in rectification of very high frequency signals. It is used in communication system circuits. It is used in AC to DC converters. It is used in Radar ... etc. It is used in welding. It is used as a light source in fibre optic communication.

List any four applications of laser diode.

Description : List any four applications of laser diode.

Last Answer : 1. As light source in fiber optic communication. 2. In the infrared spectrometers. 3. In the medical field. 4. In military applications. 5. To measure distance, alignment angle etc. 6. For flow ... . 9. For welding. 10. For sound recording and reproduction (in CD players) 11. In holography.

Draw symbol of (i) Tunnel diode (ii) LED

Description : Draw symbol of (i) Tunnel diode (ii) LED

Last Answer : (i) Tunnel diode: (ii) LED:

Describe the operating principle of PIN diode with neat sketch.

Description : Describe the operating principle of PIN diode with neat sketch.

Last Answer : Consider the structure of a PIN diode as shown in fig  A PIN diode operates under what is known as high-level injection.In other words,the intrinsic i region is flooded with charge ... results in faster operation of the diode,making it a suitable device for high frequency operations.

State operating principle of LED. Write material names used to manufacture LED.

Description : State operating principle of LED. Write material names used to manufacture LED.

Last Answer : Principle of Operation of LED:  When an LED is forward biased, the electron in the n-region will cross the junction and recombine with the holes is p-type. When the recombination takes ... Gallium Arsenide Phosphite (GaAsP) : Red or Yellow. Gallium Phosphite (GaP) : Red or Green.

Describe the working of PN junction diode with neat sketch under forward biased condition.

Description : Describe the working of PN junction diode with neat sketch under forward biased condition.

Last Answer : If the p-region (anode) is connected to the positive terminal of the external DC source and nside (cathode) is connected to the negative terminal of the DC source then the biasing ... The large number of majority carriers crossing the junction constitutes a current called as the forward current.

Describe working of schottky diode with neat construction

Description : Describe working of schottky diode with neat construction

Last Answer : Applications: 1) RF mixer and Detector Diode. 2) Power Rectifier 3) Voltage Clamping 4) Stand-alone photovoltaic system in order to prevent batteries from discharging purpose for the ... . 7) Low Voltage Power Supply Circuits. 8) To rectify very high frequency signals.

Write working principle of photodiode and state its two applications.

Description : Write working principle of photodiode and state its two applications.

Last Answer : Working principle of photodiode:   Working principle: A photodiode is a PN- junction diode that consumes light energy to produce electric current. Sometimes it is also called as photo- ... Optical remote control Smoke detectors Flame detectors Intruder alert security system 

Explain the working principle of slug tuned inductor.

Description : Explain the working principle of slug tuned inductor.

Last Answer : The value of inductor increases, when the slug (moving coil) is moved into the coil winding and hence decreases the resonant frequency of the tuned circuit. Similarly, when the slug is moved out of the ... be varied by using movable core which can be moved up or down by using screw driver.

Explain the working principle of electrolytic capacitor.

Description : Explain the working principle of electrolytic capacitor.

Last Answer : Principle: Electrolytic capacitors are using a chemical feature of some special metals, on which by anodically oxidation, an insulating oxide layer or dielectric originates. The metal is placed in an ... form the thin oxide dielectric, this type of capacitor is called electrolytic'.

State four applications of PIN diode.

Description : State four applications of PIN diode. 

Last Answer : i. Used in rectifier circuit. ii. Used in clipping and clamping circuit. iii. Used for A.M detection. iv. Used for voltage multiplier.

Draw the characteristics of tunnel diode, showing operating regions. State two applications of tunnel diode.

Description : Draw the characteristics of tunnel diode, showing operating regions. State two applications of tunnel diode.

Last Answer : Applications: One of the important application of a tunnel diode is in high speed computers where the switching times in the order of nanoseconds or picoseconds are desirable. A tunnel diode can be ... In digital networks. 2. As a high speed switch. 3. As a high frequency oscillator.

Define dynamic resistance of diode. State, how it is calculated using forward characteristics of diode.

Description : Define dynamic resistance of diode. State, how it is calculated using forward characteristics of diode.

Last Answer : Definition: The resistance offered by the diode to the AC operating conditions is known as the Dynamic resistance' or Incremental resistance' or AC resistance' of a diode. It is ... Dynamic resistance is actually the reciprocal of the slope of the forward characteristics.

Draw construction of Schottky diode and state it’s four applications.

Description : Draw construction of Schottky diode and state it’s four applications.

Last Answer : Applications :- 1. RF mixer and detector diode: 2. Power rectifier 3. Voltage clamping 4. Stand alone photovoltaic systems in order to prevent batteries from discharging purpose for the solar panels at night 5. Rectifiers in power supplies.

State any Four applications of PN junction diode.

Description : State any Four applications of PN junction diode.

Last Answer : 1. Rectifiers in power supplies, 2. Detectors in RF, 3 .Clippers, 4. In clamping networks used as DC Restorers, 5. As switches in digital logic circuits.

Define given parameters and state their values for bridge rectifier (i) Ripple factor (ii) PIV of diode.

Description : Define given parameters and state their values for bridge rectifier (i) Ripple factor (ii) PIV of diode.

Last Answer : Ripple Factor: Ripple Factor is defined as the ratio of RMS value of the AC component of output to the DC or average value of the output. Mathematically it is expressed as, ( ... which appears across non-conducting reverse biased diode. (ii) PIV of diode for bridge rectifier-Vm

Explain with neat sketch construction of PIN Diode. Draw its characteristics in reverse bias mode.

Description : Explain with neat sketch construction of PIN Diode. Draw its characteristics in reverse bias mode. 

Last Answer : Construction A PIN diode is made up of three semiconductor materials; two heavily doped P- and N- type material separated by an intrinsic (undoped) semiconductor (I) as shown in above figure ... . This advantage allows the PIN diode to process even weak signals.  Characteristics

Draw the clipper circuit using series and shunt diode.

Description : Draw the clipper circuit using series and shunt diode.

Last Answer : Fig: A series negative clipper (OR) Fig: Series positive clipper Fig: Parallel positive clipper (OR) Fig: Parallel negative clipper

List four specifications of zener diode or P- N junction diode.

Description : List four specifications of zener diode or P- N junction diode.

Last Answer : Specifications of zener diode: 1. Zener voltage 2. Power dissipation 3. Maximum power dissipation PD(max) 4. Breakdown current 5. Dynamic resistance 6. Maximum reverse current. (OR) ... Reverse saturation current 5. Power dissipation 6. Junction temperature 7. Peak inverse voltage (PIV)

Write two applications of P-N junction diode and zener diode.

Description : Write two applications of P-N junction diode and zener diode. 

Last Answer : Application of P-N junction diode: Used in rectifier circuit Used in clipping and clamping circuit. Used for A.M detection Used for voltage multiplier. Application of Zener diode: It is ... . Used in protection circuits for MOSFET. Used in pulse amplifier. Used in clipping circuits.

Draw the characteristics of tunnel diode and write two applications of it.

Description : Draw the characteristics of tunnel diode and write two applications of it.

Last Answer :  Characteristics:  Applications: 1. In the digital networks 2. As a high speed switch 3. As a high frequency oscillator 4. High speed computers

Draw and explain V-I characteristics of a P-N junction diode.

Description : Draw and explain V-I characteristics of a P-N junction diode.

Last Answer : V-I Characteristics of a P-N junction: V-I characteristics of a Diode: The V-I characteristics can be divided in two parts. 1. Forward characteristics. 2. Reverse ... plot a graph with reverse voltage on horizontal axis and current on vertical axis, we obtain reverse characteristics.

Compare P-N junction and Zener Diode.

Description : Compare P-N junction and Zener Diode.

Last Answer : P-N junction Zener Diode It conducts in only in one direction.  It conducts in both the directions. It is always operated in forward bias condition. It is always operated in ... . It cannot be used for rectification, but commonly used for voltage regulation

Draw V-I characteristics of p-n junction diode? Define static and dynamic resistance of diode.

Description : Draw V-I characteristics of p-n junction diode? Define static and dynamic resistance of diode.

Last Answer : Static Resistance: The resistance offered by a p-n junction diode when it is connected to a DC circuit is called static resistance.  (OR) It is the ratio of DC voltage applied across diode ... The dynamic resistance of a diode is the ratio of change in voltage to the change in current. 

Define static and dynamic resistance of diode.

Description : Define static and dynamic resistance of diode.

Last Answer : Static resistance (Rf) :Static Resistance of a P-N junction diode is the ratio of forward voltage to forward current.   Dynamic Resistance (rf): Dynamic Resistance of a P-N junction diode ... small change in forward voltage to small change in forward current at a particular operating point.  

List any two applications of photo diode and IRLED

Description : List any two applications of photo diode and IRLED 

Last Answer : Photodiode 1. In the cameras for sensing the light intensity. 2. In CD players. 3. In the fiber optic receiver. 4. As photo (light) detector. 5. In light intensity meters. 6. In the ... shaft encoders 4. As a light source in optical fiber system 5. In the burglar alarm system.

List any two applications of Schottkey diode.

Description : List any two applications of Schottkey diode.

Last Answer : Application of Schottky diode: • It is used in rectification of very high frequency signals. • It is used in communication system circuits. • It is used in AC to DC converters. • It is used in Radar system. • It is used in switched mode power supply. 

Draw and describe the VI characteristics of zener diode

Description : Draw and describe the VI characteristics of zener diode

Last Answer : A zener diode is operated only in the reverse-bias region. (generally written as VR) is increased, the reverse current (usually called zener current, IZ) remains negligibly small up to ... out of the breakdown region, when the applied reverse voltage is reduced below the breakdown voltage.  

Draw VI characteristics of Tunnel diode & describe it.

Description : Draw VI characteristics of Tunnel diode & describe it.

Last Answer : Symbol of TUNNEL DIODE operating principle of tunnel diode Working  The operation of tunnel diode is based on special characteristics known as negative resistance. The width of the ... tunneling & hence the name of the high impurity density PN junction is called as tunnel diode.

Which material is used for manufacturing of following LED ? (i) Infrared LED (ii) Red or Green LED (ii) Red or Yellow LED (iv) Blue LED

Description : Which material is used for manufacturing of following LED ? (i) Infrared LED (ii) Red or Green LED (ii) Red or Yellow LED (iv) Blue LED

Last Answer : Infrared LED : Aluminum gallium arsenide (AlGaAs) Red or Green LED: Indium gallium nitride (InGaN), Aluminum gallium arsenide (AlGaAs) Red or Yellow LED : Aluminum gallium indium phosphide (AlGaInP), Aluminum gallium arsenide (AlGaAs) Blue LED : Indium gallium nitride (InGaN)

Draw and describe construction of LED .

Description : Draw and describe construction of LED .

Last Answer : Construction of LED Fig above shows the construction of LED. Here an N-type layer is grown on a substrate by a diffusion process. Then a thin P-type layer is grown on ... takes place. After passing through the P-region the light is emitted from the window provided at top.

Write two applications of i) LED ii) photodiode.

Description : Write two applications of i) LED ii) photodiode.

Last Answer : LED:   1. In the opto- couplers.  2. In the infrared remote controls.  3. As indicators in various electronic circuits.  4. In seven segment and alphanumeric displays.  5. In optical switching ... As photo (light) detector.  5. In light intensity meters.  6. In the object counting system. 

Describe the operating principle of photodiode with sketch

Description : Describe the operating principle of photodiode with sketch

Last Answer : Operating principle of photodiode: A photodiode is a PN junction or PIN structure. When a photon of sufficient energy strikes the diode, it excites an electron, thereby creating a mobile electron ... ) along its direction while the photocurrent remains virtually the same. Diagram optional:  

Draw π-filter and state its working.

Description : Draw π-filter and state its working.

Last Answer : Circuit Diagram:   Working : It consists of a filter capacitor C1 connected across the rectifier output, a choke L is series and another filter capacitor C2 connected across the load RL. The ... which the choke has failed to block. Therefore, only d.c component appears across the load. 

Draw construction of PVC gang capacitor and describe it’s working.

Description : Draw construction of PVC gang capacitor and describe it’s working.

Last Answer :  Diagram Working  In plastic core capacitor, poly-vinyl chloride (PVC) type of plastic film is used as dielectric between the fixed & movable vanes instead of air. This increases ... & results in great reduction of size of capacitor in comparison with the air core capacitor.

Explain the working of TDR along with its symbol and characteristics.

Description : Explain the working of TDR along with its symbol and characteristics. 

Last Answer : TDR are also called as thermistors. Thermally sensitive materials are used to manufacture thermistors. Depending on the temperature co- efficient of resistance value thermistors are classified as ... used when a drastic change in resistance is required at specific temperature. RαT

Draw the constructional diagram of iron core inductor and write the working of it.

Description : Draw the constructional diagram of iron core inductor and write the working of it.

Last Answer : Iron core inductors allow high inductance value but are limited in high frequency capacity due to hysteresis and eddy current losses. Iron core increases the magnetic induction of a ... certain point this result in a useful increase in inductance. Beyond that point, inductance decreases.

Draw and describe working of positive clamper.

Description : Draw and describe working of positive clamper.

Last Answer : Diagram- Operation In the first negative half cycle after turning on the circuit, the diode acts as a closed switch and charges the capacitor to peak input voltage Vm with the polarities. In all the ... Vo as,  This shows that the clamper adds a positive DC shift. Waveform

Draw and describe working of full wave rectifier using centre tapped transformer.

Description : Draw and describe working of full wave rectifier using centre tapped transformer.

Last Answer : Full wave Rectifier with Center tapped transformer(FWR): In full wave rectification, the rectifier conducts in both the cycles as two diodes are connected. Circuit diagram: Operation: 1. In ... both half-cycles of input AC voltage. Therefore DC is obtained across the load RL.

With help of circuit diagram and waveform, explain working of positive series clipper.

Description : With help of circuit diagram and waveform, explain working of positive series clipper.

Last Answer : Series Clipper (Positive):-   Working: For positive cycle the diode D is reverse biased. Hence there is no voltage across the load RL While for negative half wave, the diode D is forward biased. Hence ... positive cycle of the input voltage gets clipped off. Input & o/p wave form:-   

With help of circuit diagram and waveform, explain working of CLC or π- filter.

Description : With help of circuit diagram and waveform, explain working of CLC or π- filter.

Last Answer : Circuit diagram CLC or Π filter:   Working : It consist of a filter capacitor C1 connected across the rectifier o/p , a choke L is series and another filter capacitor C2 connected across the load. ... to block. Therefore, only d.c component appears across the load and that is what we desire.  

With help of constructional diagram, explain working of air-gang capacitor.

Description : With help of constructional diagram, explain working of air-gang capacitor.

Last Answer : Construction of air-gang capacitor : Air gang capacitors are capacitors which use air as their dielectric. The simplest air capacitors are made of two conductive plates separated by an air gap.   ... capacitor. The rotor plates are attached to the shaft that is used to adjust the capacitance. 

With help of constructiobal diagram, explain working of slug tunned inductor.

Description : With help of constructiobal diagram, explain working of slug tunned inductor.

Last Answer : The variable inductor having an adjustable ferrite core is known as slug tuned inductor. The value of inductance increases or decreases respectively, due to the movement of a ferrite core into or out of ... be varied by using movable core which can be moved up or down by using screw driver. 

With help of constructional diagram, explain working of LDR.

Description : With help of constructional diagram, explain working of LDR.

Last Answer : Working of LDR: Due to the radiant energy supplied to the semiconductor, the covalent bonds are broken and the electron hole pairs are generated resulting into flow of current. These increased ... resistance of the LDR will decrease with increase in the intensity of incident light.

Draw and explain the working of combinational Clipper with waveforms.

Description : Draw and explain the working of combinational Clipper with waveforms.

Last Answer : Explanation:- As shown in figure the combinational clipper is the combination of positive biased and negative biased clipper. The combinational clipper can be used to clip both two independent ... open circuit. Hence the value of output voltage cannot exceed the voltage level of VB2.