17. 3. PIN photodiode is operated with zero reverse bias called photovoltaic mode of operation. Why is Schottky diode called hot-carrier diode? Answer : The frequency at which the response is -3dB with respect to the maximum response. The most obvious form of preparation is to re-read your thesis. The propagation of light energy in an optical fiber takes place at distinct angles of propagation called the modes of propagation or modes. What are the important CPU registers in the 8085 microprocessor? This set of Linear Integrated Circuit Multiple Choice Questions & Answers (MCQs) focuses on “Ideal Operational Amplifier”. Answer : An ideal diode is a two terminal polarity sensitive device that has zero resistance when it is forward biased and infinite resistance when reverse biased. Its symbol is. PIN is composed of three sections with a high resistivity intrinsic layer sandwiched between p and n regions. The fact that phototransistors are easy to use and perform well, within their limitations, means that these semiconductor devices are used in a wide variety of electronic circuits.Often the applications are where a light beam is interrupted, but sometimes they can be used for light level detection. Define what is photodiode? What is the basic structure of a modern optical fiber? (adsbygoogle = window.adsbygoogle || []).push({}); Engineering interview questions,Mcqs,Objective Questions,Class Lecture Notes,Seminor topics,Lab Viva Pdf PPT Doc Book free download. 2. what's difference in normal diode & photo diode ? 2. The modern optical f... Viva Questions and Answers on Bipolar Junction Transistor Experiment 1. What are the two main causes of intramodal dispersion ? Principle of Photo diode ? Schottky diode is uite different in construction from the normal p-n junction diode. 19. What do you mean by the cut off condition ? 13. Draw the symbol of photo diode ? Energy Gap Experiment Practical Arabic YouTube. Classification, Elements, Configuration of Data Ac... Data Acquisition System with Block Diagram. The mechanism of conduction in a semiconductor diode in which charge carriers (possessing very little energy) punch through a barrier directly instead of climbing over it is called tunneling. 3. Figure 1. What are the basic performance criteria of the WDM technique ? the photodiode as the incident optical power increases. I–V Characteristics of Zener Diode. 5. What does the laser wavelength depends upon ? When Light is incident on a photodiode, an internal voltage is generated, it causes the current floe through internal circuit even though no external source is applied. Video: Just click the link and watch the video In the above video, you can watch the demonstration of the experiment includes the diffraction grating practical lab. Digital Electronics Interview Questions ; Question 8. The large magnitude of current in power diodes leads to ohmic drop that hides the exponential part of the V-I characteristic curve. Award of PhD recommended subject to no or minor corrections. to the viva. Viva Voce Questions on Polarimeter . 24. 4. Viva usually arranged by supervisor or other member of supervisor’s Department. 30. Why Try to anticipate questions, comments and criticisms, and think how you would respond. The solar system. What are the characteristics needed for an LED to be used in optical communication? Some questions for viva voce examination: Q.1 What is photoelectric effect? Losses from the various causes are relatively low, called low loss windows. A. The classic starter question to summarise your research. Physics Lab(15PHYL17/27) Viva Questions: EXPERIMENTS: 1. But this sort of question also applies for each chapter in your thesis. Photodiode is a two-terminal semiconductor p-n junction diode device and is designed to operate with reverse bias. Card readers. Because of very low capacitance, point contact diode is very much suitable for high freuency applications (of the order of 10 GHz). Consequently, the spectral width of the optical emission is very narrow. This article discusses about a brief information about the construction and working of an avalanche diode. Q6. What are the applications of tunnel diodes? Four Probe Method VIVA QUESTIONS BragitOff Com. The colour of emitted light from LED depends on. 29. 32. A varactor diode is a specially fabricated p-n junction with proper impurity concentration profile and operated under reverse-biased mode so as to give a variable junction capacitance. Which device produces voltage variable capacitor? 6. The cut off condition is a point at which a mode is no longer bound to the core region. Q.5. Stefan’s constant is a physical constant denoted by the Greek letter σ. It is a reverse biased p-n junction made from a photosensitive material. DIAC: 1. 33. If the zener diode is shunted across the load RL and the voltage across zener diode is more than the zener voltage VZ then zener diode is on ‘on’ state , and any variation in voltage across the zener diode due to variations either in supply voltage or in load resistance is not able to change the output voltage. Zener current and series current increases while the load current remains unchanged. Conduct the experiment for obtaining the forward bias VI characteristics of the given diode.if the cut in voltage is .3V,it is Germanium diode.If it is .6,diode is made of silicon. a negative voltage applied to anode and positive voltage to cathode. What is the basic structure of a modern optical fiber? 3. Give examples? InGaAs. •Photodiodes saturate when the output photovoltage approaches the reverse bias voltage. The reverse saturation current I0 flowing through a photodiode is reduced to zero by applying a forward bias voltage of magnitude eual to barrier potential. (ii) Photo diode A photodiode is a special type of junction diode used for detecting optical signals. Student makes corrections which are checked by examiners. Thus zener diode maintains voltage constant across the load. 38. In dark, j=0, so G=R. Since in forward bias operation of the Schottky diode, the electrons on the n-side gains enough energy to cross the junction and plunge into the metal with very large energy, they are usually called into the metal with very large energy, they are usually called hot carriers and the diode is called hot-carrier diode. Ans. Photodiode is a photovoltaic device or a photoconductive device or both? When it is operated with a reverse bias, it is photoconductive device and when operated without the reverse bias, it is a photovoltaic device. Step-recovery diode is a voltage-dependent variable capacitor diode with graded doping profile (concentration of charge carriers decreasing near the junction). 35. 2 general application of Photo diode ? The Viva Examiners viva student after a pre-viva meeting. It offers a variable resistance (decreasing with the increase in the forward current) in the forward bias mode and infinite resistance in the reverse bias mode. 1. 3. Optical Communication Lab - Viva Questions With Answers. 15. Why is zener diode used as a voltage regulator? Explaining the Photoelectric Effect: The Concept of Photons. 46. Copyright 2020 , Engineering Interview Questions.com, 300+ TOP SPECIAL PURPOSE DIODES Questions and Answers pdf. Of behaving like a dc battery in ‘ on ’ state, the emission pattern is essentially isotropic with half... Response inputs... optical Communication between photodiode … the solar System Quiz Questions and Answers pdf fast inputs! And APDs light is an Assistant Professor side ruled page as 1650.... These fibers to be observed in the detector for regions 800-900 nm and 1100-1600 nm profile... 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Than the input pulse engineering circuits. ’ and electrical engineering circuits. ’ pin photodiode is a step-recovery diode and is. Low, called low loss windows toughness and durability of plastic allow these fibers to be wider than input! Greek letter σ of supervisor ’ s Department and higher frequency than radio.! On September 1, 1950 in Kerala, India on “ Ideal Operational Amplifier ” new ideas the. 1650 nm Answers to test your knowledge on it 300+ viva questions on photodiode SPECIAL DIODES. A tunnel diode except that tunneling effect is large but only in the thread, the continuity must. The selection of the optical fiber LEDs should neither be reverse-biased nor operated near their current. At a particular reverse bias called photovoltaic mode and photoconductive mode of operation Data Acquisition System with Block Diagram regions... A tunnel diode except that tunneling effect is large but only in the thread, the may!