electricalengineeringquestionanswer

Frequently Asked Interview Questions on Alternators In this post we had given few Alternators related Interview questions with solutions. We believe that it will be helpful for your interview preparation. Please leave your comments in comments section. [Q] What is meant by synchronising the alternators? The process of connecting two or more alternators in parallel for supplying a common load is called synchronising. [Q] What are the conditions to be satisfied for proper synchronising of alternators? (i) The terminal voltage of the incoming alternator must be the same as bus-bar voltage. (ii) The speed of the incoming alternator must be such that its frequency equals to the bus-bar frequency (iii) The phase sequence of the incoming alternator must be the same as that of the other alternators or busbars. [Q] What are the advantages of Parallel operation of alternators? (i) It ensures continuity of power supply to consumers in case of breakdown of an alternator in an generation station. (...

Basic Electrical Engineering Interview Questions Answers 1 [Q] Define Power and Energy? The rate at which work is done in an electric circuit is known as Electric power. Power = Voltage X Current The basic unit for electric power is Watts The instrument used to measure the power is known as watt meter. The total amount of work done in an electric circuit is called as electric energy.  Energy = Power X Time the basic unit is Joule or watt-sec The practical unit is Kilo watt-hour The instrument used to measure the energy is known as Energy meter. [ Like this you have to explain elaborately in the interviews. The interviewer will expect detailed answer from the candidate. If he feels that you are deviating too much, then he will stop you and ask another question. Please don't answer in one line. Add related points where ever possible] [Q] In our house are we monitoring/measuring power or energy? Energy. It is done by energy meter. [Q] what is meant by cycle in ac waveform? what i...

Basic Interview Questions on Induction Motors: [Q] How does the Induction motor work? (OR) Why does the Rotor rotate? When the 3 phase stator windings are fed by 3 phase supply, a magnetic flux of constant magnitude which is rotating at synchronous speed is set up.  The flux passes through the air-gap and sweeps past the rotor surface  thus it cuts the rotor conductors.  Due to the relative speed between the rotating flux and the stationary rotor conductors, an emf is induced in the stationary rotor conductors as per the Faraday's laws of electromagnetic induction. The frequency of the induced emf is the same as the supply frequency. Its magnitude is proportional to the relative velocity between the flux and the conductors. Its direction will be as per Fleming's right hand rule. Since the rotor conductors form a closed circuit the rotor current is produced. This current's direction will oppose the very cause producing it ( as per Len's law) Here the cause is the...