List two applications of LDR.

1 Answer

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 optical coding.

5. It is used in the light (flux meter).

6. It is used in the photosensitive relay.

7. It is used in camera light meters.

8. It is used in the security alarms.

9. It is used in the smoke detectors.

10. It is used in the infrared astronomy.

Related questions

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.

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.

Description : Draw & describe construction of LDR

Last Answer : 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 ... of photo resistors may be several mega ohms in total darkness and less than100Ω, when well illuminated.

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.

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.

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. 

Description : List two applications of i) clipper ii) clamper.

Last Answer : Clipper:  1. Diode clamp 2. wave shaping circuits 3. Clippers can be used as voltage limiters and amplitude selectors. Clamper:  1. Voltage Multipliers 2. For the protection of the ... can be used for removing the distortions 4. For improving the overdrive recovery time clampers are used.

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.

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.

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.

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

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.

Description : Write two applications of clipper and two of clamper.

Last Answer : Application of Clipper:  In the case of generating new waveforms and/or shaping the existing older waveforms. Clippers can be used as freewheeling diodes in protecting the transistors from transient ... called as direct current restorers as they clamp the wave forms to a fixed DC potential.

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 

Description : What is magnetic material ? State it’s two applications.

Last Answer : Magnetic materials are those materials that can be either attracted or repelled when placed in an external magnetic field and can be magnetized themselves. OR The materials which provide path to ... . Applications: 1.Floppy disc ,hard disc  2.Motors and generators  3.Biomedical equipment

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. 

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.

Description : Write the specifications of linear and non- linear potentiometers. State its applications

Last Answer : Specifications of linear & nonlinear potentiometers:  1. Ohmic range: 10Ω to 125 kΩ 2. Power rating : 100watt to 200 watt 3. Tolerance :  2% 4. Voltage Rating: 5V-500V 5. Operating ... 7. Used as potential dividers. 8. It is used for panel control in receivers, function generator etc 

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.

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.

Description : List specifications of resistors and explain any two.

Last Answer : List specifications of resistors are as follows: 1. Maximum voltage rating. 2. Power rating. 3. Temperature co- efficient of resistance. 4. Tolerance. 5. Operating temperature. 6. Ohmic ... form of energy. Tolerance: It is defined as deviation from nominal value of resistance in percent.

Description : List the two advantages of Bridge Rectifier. 

Last Answer : The advantages of bridge rectifier: The output is twice that of the center-tap circuit for the same secondary voltage. The PIV is one half that of the center-tap circuit. The ... and hence transformer losses are reduced. It can be used in applications allowing floating output terminals. 

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)

Description : Give the classification of resistors. List any four materials used for manufacturing of resistors.

Last Answer : Materials used for manufacturing of resistors: Carbon Composition Resistor (carbon dust or graphite paste) Film or Cermet Resistor (conductive metal oxide paste) Nichrome, enamel LDR- Cadmium sulphide, Cadmium selenide, lead sulphide TDR- Cobalt, Nickel, Manganese

Description : List four dielectric materials used for capacitors. 

Last Answer : 1. Mica, glass, ceramic 2. High permittivity ceramic 3. Paper and metallized paper 4. Electrolytic : Oxide film, tantalum 5. Dielectrics such as polystyrene, polythene polytetrafluoroethylene.

Description : List different types of capacitors? State the dielectric materials used for it.

Last Answer : Types of capacitors: 1. Electrolytic capacitor 2. Variable capacitor 3. Air ganged capacitor 4. PVC ganged capacitor 5. Trimmer capacitor Dielectric materials used in capacitors: 1. Air 2. ... Ceramic 5. Porcelain 6. Polystyrene. 7. Fibre 8. Bakelite 9. Waxed paper 10.Plastic

Description : List four specifications of resistor.

Last Answer : specifications of resistor: 1. Resistance value 2. Tolerance 3. Power rating 4. Maximum operating temperature 5. Maximum operating voltage 6. Frequency range 7. Temperature coefficient of resistance 8. Wattage

Description : State any two applications of LDR. 

Last Answer : i) In camera for exposure control ii) In photocopy machine iii) In security alarms iv) As smoke detector v) In street light control 

Description : Write the function of C and L in π filter and write two advantages of π filter over other filters.

Last Answer : The capacitors C1 and C2 provide a low reactance path for the ripple whereas the series inductor L provides a high reactance to the ac ripple. The combined effect of this is the reduction in ripple, and ... very low. 4. High dc voltage (approximately Vm) 5. Increase in the average load voltage. 

Description : State two functions of slug- tuned inductor and write the expression of self-inductance.

Last Answer : It is kind of variable inductor. The value of inductance increases, when the slug is moved into the coil winding and decreases the resonant frequency. When the slug is moved out of the coil ... decreases and resonant frequency of the tuned circuit increases. Self-inductance (L)= N x φ /I

Description : State any Four specifictions of capacitor and explain any two in details.

Last Answer : Specifictions of capacitor: 1.Dielectric material 2.Capacitance value 3.Working voltage 4.Tolerence 5.Temperature coefficient 6.Power factor 7.C/V ratio 9.Insulation resistance Explanation: 1.Working ... side from actual value. 4.C/V ratio: It is the ratio of capacitance to volume.

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.

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.

Description : Define rectification efficiency. Give its formula.

Last Answer : The ratio of output DC power delivered to the load to the applied input AC power is called rectification efficiency. It is denoted by η. η = Output DC power delivered to the load / Input AC power from transformer secondary η = Pdc / Pac

Description : Define permeability and reluctivity of magnetic material. 

Last Answer : Permeability is the capability of a specific material to allow the flow of magnetic flux more easily. Thus higher permeability enables a material to pass more magnetic flux. Reluctivity is equal to the ratio of the intensity of the magnetic field to the magnetic induction of the material.

Description : Define following terms: i) Active networks. ii) Unilateral networks

Last Answer : i) Active networks: If a network consists of an energy source then it is called an active network. The type of energy source can be a voltage source or a current source. ii) ... direction of current through its elements in it, then the network is called as a unilateral network.

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.

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

Last Answer : star and delta connection

Description : Explain the following terms 1. Bilateral Network 2. Linear Network

Last Answer : Bilateral Network If the magnitude of current flowing through a circuit element is not affected when the polarity of the applied voltage is changed, then the element is known as a bilateral element. ... network comprising of one or more linear number of elements is known as a linear network.

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

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

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

Last Answer : Circuit Diagram Bridge rectifier

Description : Draw a label diagram of ferrite core inductor.

Last Answer : Ferrite core inductor

Description : Convert the delta network into equivalent star network.

Last Answer : Delta to start network R1 = 4x6/ 4+6+2 = 24/12 =2/1= 2Ω R2 = 2x6/ 4+6+2 = 12/12= 1 = 1Ω R3 = 4x 2/ 4+6+2 = 8/12= 2/3= 0.66Ω

Description : Compare: 1. Active and passive network 2. Linear and non-linear network

Last Answer : 1. Active network and passive network. Sr.No Active network Passive network 1 If a network consists of an energy source, then it is called as an active network. If ... only to the linear networks.  The superposition theorem also is not applicable to the nonlinear networks.

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

Description : Compare clipper and clamper

Last Answer : Sr. No Parameter Clipper Clamper 1 Components used Diode, Resistors  Diode, Capacitors, Resistors 2 Function To remove a part of input waveform To add a DC ... Application Diode clamp, wave shaping circuits  Voltage Multipliers  5 Configuration

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

Description : Explain the colour coding using colour band system in capacitor with an example.

Last Answer : 1. First and second band gives the significant digit reading from left to right. 2. Third colour band gives the multiplier. 3. Fourth colour band gives the tolerance value. 4. Fifth and sixth bands ... , Violet, Yellow To find : Value of capacitor Solution: Yellow: 4  Violet: 7

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.