# Pe lab viva questions and answers pdf

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What is Power electronics?

## Power Electronics Viva Questions with Answers

Engineering Interview Questions. It's Free! Go to pdf-convert. What is holding current in SCR? It is the minimum current required to hold the SCR in forward conduction state. When the forward current becomes less than holding current, SCR turns from forward conduction state to forward blocking state. What is latching current in SCR? It is the minimum current required to latch turn on the SCR from forward blocking state to forward conduction state.

What are the different turn on methods of SCR? What is snubber circuit? It is a series combination of a resistor and a capacitor in parallel with the SCR. What is hard switching of the thyristor? When gate current is several times higher than the required gate current, the SCR is said to be hard fired. What is firing angle? The angle between the zero crossing of the input voltage and the instant the SCR is fired is called as delay angle or firing angle.

What is meant by SOA? SOA Safe Operating Area determines the voltage and current boundary within which the Power Device can be operated without destructive failure.

What are the main components used for isolating the Power Circuits, Power Semiconductor from the low-power circuit? Opto-Couplers, Transformers 9. What is duty cycle? It is the ratio of the ON time of the chopper to total time period of the chopper. Can fuses with an AC voltage rating be used in a DC applications? Fuses must be rated for the voltage AC or DC in which they will be used.

Generally, fuses have a DC voltage rating that is half of the maximum AC voltage rating. What are the characteristics of ideal Opamp? Infinite open loop voltage gain Infinite input impedance Zero output impedance Infinite Bandwidth Zero offset voltage General rule of thumb is for low-frequency applications having frequency range upto 20kHz, we have to use IGBT. What are the advantages of free wheeling diode in rectifier circuit?

The input power factor is improved. It prevents the output voltage from becoming negative. The Load current waveform is improved. The process of changing the direction of current flow in a particular path of the circuit. It is used to turn off the SCR. What are the types of commutation? Natural commutation Forced commutation What is natural commutation?

What is forced commutation? The process of the current flowing through the thyristor is forced to become zero by external circuitry is called as forced commutation. What are the types of commutation with respect to commutation process?

Voltage commutated chopper Current commutated chopper Load commutated chopper What is meant by cyclo-converter? It is also known as frequency changer. It converts input power at one frequency to output power at another frequency with one stage conversion. What are the types of cyclo-converters? Step up cyclo-converter Step down cyclo-converter.

What is step down cyclo-converter? It is the converter whose output frequency is less than the input frequency. What is step up cyclo-converter? It is the converter whose output frequency is more than the input frequency. What does the Voltmeter in AC mode show? Is it RMS value or peak value? What is the necessity to use the special machines? General purpose motors Induction motors, synchronous motors are neither precision speed nor precision position motors.

For many automated systems require high precise speed and high precise positioning motors. In such cases special purpose motors like stepper motors, PMDC motors etc. What are the control strategies of chopper? The control strategies of chopper are 1.

What is delay angle or what is firing angle of phase controlled rectifier? The delay angle is the angle at which thyristors are triggered after zero crossing. After zero crossing of supply voltage, one pair of thyristors is forward biased. What is Universal Motor? It is defined as a motor which can be operated either on DC or single-phase AC supply at approximately the same speed and output.

The universal motor is built exactly like a series DC motor. But a series DC motor cannot be run as a universal motor, even though both motors look the same internally and externally.

It has high starting torque and a variable speed characteristic. It runs at dangerously high-speed on no load. Give some examples of power electronics applications in the day-to-day life?

We can list a huge number of power electronics applications. What is meant by PMDC? There are three types of permanent magnets used for such motors namely; i Alnico Magnets ii Ceramic magnets iii Rare-earth magnets The major advantages are low noise, small size, highefficiency, low manufacturing cost. Thank you! Engineering interview questions,multiple choice questions,objective type questions,seminor topics,lab viva questions and answers ,online quiz test pdf free download for freshers.

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With this revised edition we aim to present a text on Power Electronics for the UG level which will provide a comprehensive coverage of converters, choppers, inverters and motor drives. The third generation of SiC FETs enabled improved power conversion efficiency in many upcoming and existing application areas. Every part starts at an initial level and is so grown continuously that a normal understudy can grasp the topic effortlessly. Power electronics is the engineering study of converting electrical power from one form to another. Power Electronics By P. S Bimbra Free Download Pdf The book starts with the investigation of remarkable elements of force diodes, power transistors, MOS- controlled thyristors furthermore other related themes. Partial table of contents: Overview of Power Semiconductor Switches.

Electronics Engineering students need to face some Basic Electronics Questions whether they are preparing for an interview or viva voce. So, this article gives you few Basic Electronics Questions for Interview and other competetive exams. Generally, you need to refer a variety of books in order to cover the ocean of topics in Electronics. What is an ideal voltage source? Answer: A device with zero internal resistance. What is an ideal current source?

Cars lose some of their value each year through typical aging and daily wear and tear. Power Electronics Objective Questions 1. Transmission and Distribution of Electrical Power. The text is written for some flexibility in the order of the topics. Transformer design Edit Any switched-mode power supply that gets its power from an AC power line called an "off-line" converter [33] requires a transformer for galvanic isolation.

## Basic Electronics Questions for Interview

Mechanical Engineering 1. MCQ Practice Tests. Timed Mock Tests. Online Quizzes. Technical Terms.

What is holding current in SCR? It is the minimum current required to hold the SCR in forward conduction state. When the forward current becomes less than holding current, SCR turns from forward conduction state to forward blocking state. What is latching current in SCR?

The steel used is of high silicon content sometimes heat treated to produce a high permeability and a low hysteresis loss at the usual operating flux densities. Which material is used for the core of a transformer and why. Eee lab viva questions with answers 1.

### 100+ TOP POWER ELECTRONICS LAB VIVA Questions and Answers

Login to your account with your ID and password. Unlike Project Gutenberg, which gives all books equal billing, books on Amazon Cheap Reads are organized by rating to help the cream rise to the surface. Either B or C. Once you have finished, review the Answer Key below and compare your answers. The final exam will consist of questions developed from the course content and module quizzes. Questions 25 Publications 26, Get the organizer to provide pdf. Electricity always travels to ground 3.

Engineering Interview Questions. It's Free! Go to pdf-convert. What is holding current in SCR? It is the minimum current required to hold the SCR in forward conduction state.

#### COMMENT 3

• Pre intermediate english level pdf a three component conceptualization of organizational commitment pdf Guadalberto A. - 22.05.2021 at 04:05
• What is holding current in SCR? What is latching current in SCR? What aturn on methods of SCR? What is snubber circuit? What is hard switching of the thyristor? What is firing angle? What is meant by SOA? What are the main components used for isolating the Power Circuits, Power Semiconductor from the low-power circuit? Dana M. - 22.05.2021 at 23:21
• Question No. What is the op amp? Answer: An operational amplifier (or an op​-amp) is an integrated circuit. Fiacre S. - 23.05.2021 at 06:02