Draw & describe construction of LDR

Draw & describe construction of LDR
by

1 Answer

Answer :

image

Description: 1. Photo resistors (or LDR) are manufactured from photo-conductive semiconductor materials such as cadmium sulphide (CdS), cadmium selenide (CdSe) and lead sulphide (PbS). 2. These resistors have a ceramic substrate, over which a layer of cadmium sulphide (CdS) is deposited in zig-zag form to increase the length. This increases the resistance value. 3. Depending upon the thickness, surface area and length of the layer, the resistance value changes. The electrodes are formed by evaporating metal in vacuum. 4. The leads are connected and put in plastic case. These are available in the form of discs with wire lead ends on one side. 5. The resistance of photo resistors may be several mega ohms in total darkness and less than100Ω, when well illuminated.

by

Related questions

List two applications of LDR.

Description : List two applications of LDR.

Last Answer : 1. It is used for automatic contrast of brightness control in television receivers. 2. It is used as a proximity switch. 3. It is used in the street light control circuits. 4. It is used in the ... security alarms. 9. It is used in the smoke detectors. 10. It is used in the infrared astronomy.

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.

With the help of constructional diagram, explain the working of LDR with neat sketch.

Description : With the help of constructional diagram, explain the working of LDR with neat sketch.

Last Answer : Working Principle The resistance depends on the intensity of light, as resistance decreases with increase in light intensity. Characteristics Applications of LDR 1. They are often ... circuits, light intensity meters, for counting the packages moving on a conveyor belt, etc.

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.

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.

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 construction diagram of air core inductor. List two applications

Description : Draw the construction diagram of air core inductor. List two applications

Last Answer : Applications: i. It is used for construction of IF and RF tuning coils. ii. It is used for interstage coupling.

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.

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.

Draw & describe working of bridge rectifier with its input output waveforms

Description : Draw & describe working of bridge rectifier with its input output waveforms

Last Answer : Four diodes are used. a)In positive half cycle Diodes D1 & D3 becomes forward biased they will conduct & current flows at that time D2 and D4 are reverse biased they will not ... at that time D1 and D3 are reverse biased they will not conduct. we get full cycle rectification.

Describe construction of Aluminium Electrolytic capacitor.

Description : Describe construction of Aluminium Electrolytic capacitor.

Last Answer : A plain foil dry electrolytic capacitor is made by forming a coating of aluminium oxide on both sides of an aluminium foil. Two strips of aluminium foil used are then separated by two layers of porous ... is rolled up the ends closed with wax and then sealed into an aluminium container.

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.

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 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.

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 and describe working of series biased clipper with input output waveforms.

Description : Draw and describe working of series biased clipper with input output waveforms. 

Last Answer : Biased series positive clipper: Clipping of the signal takes place as soon as the input signal goes positive. If we want to change/adjust the clipping level of AC voltage, then external biasing voltage must be ... voltage must be used. The figure given below shows a biased (series) clipper.    

Draw and describe constructional diagram of electrolytic capacitor.

Description : Draw and describe constructional diagram of electrolytic capacitor.

Last Answer : Electrolytic capacitor is a polarized capacitor. This type of capacitor consists of pasty, semiliquid electrolyte between aluminum foil electrodes or plates. An electrolytic capacitor is a type ... the ends closed with wax and then sealed into an aluminium container as shown in fig. 

Draw and describe circuit diagram of centre tapped rectifier with LC filter along with its input and output waveforms.

Description : Draw and describe circuit diagram of centre tapped rectifier with LC filter along with its input and output waveforms.

Last Answer : Explanation: A centre- tap full wave rectifier drive produces the rectified voltage and it drives the LC filter. We know that the series inductor filter is preferred for low values of load resistance ( ... load RL. The output voltage waveforms are similar to that as shown in figure above.  

Draw the star and delta connection. State any one conversion formula.

Description : Draw the star and delta connection. State any one conversion formula.

Last Answer : star and delta connection

Draw the circuit diagram of bridge rectifier and label it.

Description : Draw the circuit diagram of bridge rectifier and label it. 

Last Answer : Circuit Diagram Bridge rectifier

Draw a label diagram of ferrite core inductor.

Description : Draw a label diagram of ferrite core inductor.

Last Answer : Ferrite core inductor

State the condition for RC differentiator. Draw the output waveform of RC integrator for square wave input.

Description : State the condition for RC differentiator. Draw the output waveform of RC integrator for square wave input.

Last Answer : Condition for RC differentiator: If the time duration T of the input waveform is comparable with the RC time constant (product of R and C) then the output waveform of the differentiator gets distorted. Hence for proper differentiator the condition is as follows: T >>RC

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

Draw the circuit diagram of shunt capacitor filter along with full wave rectifier. Draw the waveform of full wave rectifier output and shunt capacitor filter output.

Description : Draw the circuit diagram of shunt capacitor filter along with full wave rectifier. Draw the waveform of full wave rectifier output and shunt capacitor filter output.

Last Answer : Fig: Shunt capacitor filter along with full wave rectifier Fig: Waveform of full wave rectifier output and shunt capacitor filter output.

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.

Define Ferromagnetic materials. Draw B- H Curve.

Description : Define Ferromagnetic materials. Draw B- H Curve.

Last Answer : Ferromagnetic materials: The materials which possess magnetism in the absence of applied magnetic field is known as ferromagnetic materials.

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 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.

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

Draw the B-H curve for hard and soft magnetic material.

Description : Draw the B-H curve for hard and soft magnetic material.

Last Answer : Diagram: The B-H curve for hard and soft magnetic material

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.

Draw RC differentiator circuit.

Description : Draw RC differentiator circuit.

Last Answer : RC differentiator circuit :

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

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

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

Define Inductor. Draw its symbol.

Description : Define Inductor. Draw its symbol. 

Last Answer : An inductor is a passive electronic component that stores energy in the form of a magnetic field  

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. 

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 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. 

Draw labeled diagram of air core inductor.

Description : Draw labeled diagram of air core inductor.

Last Answer : Diagram of air-cored inductor :

Draw and explain B-H curve.

Description : Draw and explain B-H curve.

Last Answer : Diagram: Explanation: B-H curve is obtained while plotting the graph between B & H for a magnetic material while magnetized through one complete cycle of magnetization. The value of ... measure of the energy dissipated due to hysteresis, more the area higher is the hysteresis loss. 

Draw circuit diagram and waveforms for centre-tap full wave rectifier.

Description : Draw circuit diagram and waveforms for centre-tap full wave rectifier.

Last Answer : Circuit Diagram:    

Define clipper. Draw circuit of negative shunt clipper.

Description : Define clipper. Draw circuit of negative shunt clipper.

Last Answer : Clipper: A clipper is a device designed to prevent the output of a circuit from exceeding a predetermined voltage level without distorting the remaining part of the applied waveform. OR Clipper: An ... the positive or negative peak or both from a specific level is known as clipper.

Draw BH Curve and define coercivity and reluctivity.

Description : Draw BH Curve and define coercivity and reluctivity.

Last Answer : BH Curve: Definitions: Coercivity: For ferromagnetic material the coercivity is the intensity of the applied magnetic field required to reduce the magnetization of that material to zero after the ... to the ratio of intensity of the magnetic field to the magnetic induction of the material. 

Draw negative clamper circuit and explain its working.

Description : Draw negative clamper circuit and explain its working. 

Last Answer : Diagram: Working: During the positive half cycle of the input AC signal, the diode is forward biased and hence no signal appears at the output. In forward biased condition, the diode allows ... - 2Vm} which have the same polarity with each other. As a result, the signal shifted downwards. 

Draw the symbol of i) Iron core inductor ii) variable capacitor iii) resistor iv) Ferrite core inductor

Description : Draw the symbol of i) Iron core inductor ii) variable capacitor iii) resistor iv) Ferrite core inductor

Last Answer :  Iron core inductor:  Ferrite core inductor:  

Draw ideal and practical voltage source and current source.

Description : Draw ideal and practical voltage source and current source.

Last Answer : Voltage Source: Current Source:

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.

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 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:  

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.