we connect large capacitor bank in series to improve the voltage power supply at the load end in balanced transmission line when there is considerable voltage drop along the balanced transmission line due to high impedance of the line.So in order to bring the voltage at the load terminals within its limits (i.e (+ or – %6 )of the rated high terminal voltage )the large capacitor bank is used in series. Firstly I would like to say thank you for all your great work .Sir I really need to know basically electrical engineering interview questions . Which type of oil is used as a transformer oil? Starting methods: Synchronous motor can be started by the following two methods: 161. Where should the lighting arrestor be placed in distribution lines? Define the following: Average demand, Maximum demand, Demand factor, Load factor. A generating stations is supposed to fed power to the grid and in case generating units are off,there is no generation in the plant then plant may take power from grid. What is 2 phase motor? The armature flux has an important role for the running condition. Electrical Engineering Interview Question And Answer-Basic Electrical Part 1 Electrical Engineering 200 Important Interview Questions With Answers PDF. 197. Pu stands for per unit in power system. 26. what is meant by armature reaction? We know there are three types of power in Electrical as Active, apparent & reactive. How can you relate power engineering with electrical engineering? Resolution:Mainly transformer has high inductance and low resistance.In case of DC supply there is no inductance ,only resistance will act in the –> electrical circuit. Only one of the terminals is evident in the earth resistance. What is encoder, how it function? 47. so, interchanging of terminals in ac system does not show any difference. At first calculate the electrical current of the load, after that derate the electrical current considering derating factor(depending on site condition and laying of cable) after choose the cable size from cable catalog considering derating electrical current.After that measure the length of cable required from supply point of load to load poin. What will happen when power factor is leading in distribution of power? The choice of electrical system for an aero turbine is guided by three factors: 183. It is the voltage at which a CT gets saturated. online ups having high volt and amp for long time backup with with high dc voltage.but ups start with v dc with 7 amp. The voltage induced in secondary coil is known as mutually induced voltage. Starting current is reduced 3-4 times of the direct current due to which voltage drops and hence it causes less losses. for railways,trams, trolleys etc). Why transformer ratings are in kva? Hence the starting current is reduced , the voltage drops during the starting of motor in systems are reduced. 36. It allows control of the power flow between two 121. What is the difference between Isolator and Circuit Breaker? The effect of armature flu to main flux is called armature reaction. Starting in the early 170s, concerns about the toxicity of PCBs have led to their banning in many countries. 2. A synchronous motor takes a leading current when over excited and therefore behaves like a capacitor. Comparison of JFET’s and MOSFET’s: 192. Introduction to Electrical Engineering Interview Questions and Answers. first the load on it must be made zero and then it can safely operated. Those two have the same supply. Zener-breakdown or Avalanche breakdown may occur independently or both of these may occur simultaneously. The armature flux may support main flux or opposes main flux. communication lines.So we can understand the importance of power measurement through power quality meters. 56. What will happen if DC supply is given on the primary of a transformer? Star delta starter is preferred with induction motor due to following reasons: 142. Indrajit Mondal 103. And electrical engineering & electronics engineering ? Hence, voltage is induced in both the windings. Thus is due to negligible small leakage current. The voltage induced in the primary winding is due to its self inductance and known as self induced emf and Why field rheostat is kept in minimum position while armature rheostat at maximum position? This is usually done by means of a programmed algorithm,especially if any part is digital, while most analog encoding is done with analog So it should be zero lagging like inductor. Define what is power quality meter ? 78. I have a test in oil and gase company as a electrical engineer after some days.please guide me the preparation for this test. ACSR means Aluminium conductor steel reinforced, this conductor is used in transmission & distribution. 53. Explain the terms real power, apparent power and reactive power for ac circuits and also the units used. Thin film resistors- It is constructed as a thin film of resistive material is deposited on an insulating substrate. I thing it’s good one 4 me thanks, Your email address will not be published. We can not start the Induction motor and Synchronous motors on load, but can not start the DC series motor without load. Junctions that experience breakdown above 5v are caused by avalanche-effect. Can we measure over voltage and over current by measuring current only? What is meant by regenerative braking? This volt will capable of to break the electrons inside the tube to make electron flow. 200. Add New Question. 143. 4. Availability: As the percentage of the time a unit is available to produce power whether needed by the system or not. The avalanche breakdown occurs in lightly doped junctions, which produce wide depletion layers. The pulses are integrated (filtered or averaged) to get a steady DC voltage which is proportional to frequency. 88 Electrical Engineer Interview Questions and Answers - PDF - 8/09/2018 08:29:00 PM If you are preparing to interview a candidate or applying for a job, review this list of top Electrical Engineer interview questions and answers. A two phase motor is often a motor with the the starting winding and the running winding have a phase split. e.g; ac servo motor. Slip can be defined as the distinction between the flux speed (Ns) and the rotor speed (N). step up an unregulated dc input voltage to produce a regulated dc output voltage using a circuit known as Boost Converter or Step-Up SMPS. (p.u=actual value/base value). 101. 34. Esters are non-toxic to aquatic life, readily biodegradable, and have a lower volatility and higher flash points than mineral oil. CMRR: It can be defined as the ratio of differential voltage-gain to common made voltage gain. Hence, according to Faraday’s laws of electromagnetic induction, emf will be induced in both the windings. So delta / star transformer is used for lighting loads. 117. This flux is linked with primary and secondary windings. • Reliability, Its functions are to insulate, suppress corona and arcing, and to serve as a coolant. 80. Engineering: Sub Category Is: Electrical Engineering Interview Questions: Total Questions: 104: Electrical Engineering Interview Guide Visited: 10416 Times Electrical Engineering Interview PDF Uploaded: 8/24/2012 Last PDF Updated: 04/09/2018 Electrical Engineering PDF Downloaded: 10125 Time(s) Sir am completing my electrical engineering diploma this year ….can you send me a PDF of questions answers for my first interview preparation I will be very thankful to you…. The difference between the electronic and ordinary electrical regulator is that in electronic regulator power losses are less because as we decrease the speed the electronic regulator gives the power needed for that particular speed but in case of ordinary rheostat type regulator, the power wastage is same for every speed and no power is saved.In electronic regulator, triac is employed for speed control by varying the firing angle speed and it is controlled but in rheostatic ,control resistance is decreased by steps to achieve speed control. The complete wire wound resistor is coated with an insulating material such as baked enamel. 73. If the neutral is not grounded, fault current will definitely high and that full fault current will come back through ELCB, and there will be no difference in current. why earth pin diameter is higher than other two pin? Variable losses or copper losses: when the transformer is loaded, current flows in primary and secondary windings, there is loss of electrical energy due to the resistance of the primary winding, and secondary winding and they are called variable losses. various mediums are used to quench this arc in respective CB’s. The above mentioned are few electrical interview questions and answers. What is the difference between MCB & MCCB, Where it can be used? Define Transfer Function? 220v AC rating. Extra energy in the high wind speed region of the speed – duration curve can be extracted. The code may serve any of a number of purposes such as compressing information for transmission or storage, encrypting or adding redundancies to the input code, or translating from one code to another. Why electricity in India is in the multiples of 11 like 11kv, 22kv, 33kv ? They lead engineering teams, prepare drawings, write reports, and train new engineers. according to Lenze’s law it will oppose the cause i.e. Constant losses or Iron losses: The losses that occur in the core are known as core losses or iron losses. Due to existing current flow the air in the gap is ionized and results in the arc. Common engineering interview questions and answers So, your CV made it to the shortlist and you have an interview lined up for a job at an engineering firm. These wires are made of materials such as Constantan and Manganin because of their high resistivity, and low temperature coefficients. Normally it is used where normal current is more than 100A. What is the difference between isolators and –>electrical circuit breakers? ups is also two types : on line and offline . Below are some common interview questions for engineers, along with some guidance on how to answer them. 94. Resolution:In DC motors, Voltage equation is V=Eb-IaRa (V = Terminal voltage,Eb = Back emf in Motor,Ia = Armature current,Ra = Aramture resistance).At starting, Eb is zero. Why ELCB can’t work if N input of ELCB do not connect to ground? Why, when birds sit on transmission lines or current wires doesn’t get shock? SF6 is Sulpher hexa Flouride gas.. if this gas is used as arc quenching medium in a Circuitbreaker means SF6 CB. • Maximum demand, What is your background? 23. Essentially dc motors are utilized for electric traction systems. Refrigerators – Capacitor split phase motors. Explain What is use of lockout relay in ht voltage? DC Series motor has high starting torque. 120. 191. Wire wound resistors – length of wire wound around an insulating cylindrical core are known as wire wound resistors. more current(V constant),result in more losses if pf is good ex: 0.95 to meet actual power load has to draw less current(V constant),result in less losses). In electronic regulator triac is employed for speed control. What is the power factor of an alternator at no load? Your answers to these questions should show your knowledge of the job, as well as your ability to present information clearly and logically. Both have the same principle of electromagnetic induction, the only difference is that their construction. 15 Toughest Interview Questions and Answers! So high electrical current will flow through primary side of the transformer.So for this reason coil and insulation will burn out. The machine is started as a squirrel cage induction motor first. 187. If we connect tapings to low voltage side, sparks will produce while tap changing operation due to high current. 81. Desired results are obtained by either trimming the layer thickness or by cutting helical grooves of suitable pitch along its length. Resolution:Knee point voltage is calculated for electrical Current transformers and is very important factor to choose a CT. LA is installed outside and the effect of lightning is grounded,where as surge arrestor installed inside panels comprising of resistors which consumes the energy and nullify the effect of surge. What is the difference between surge arrestor and lightning arrestor? 24. 87. Resolution:It depends upon R=rho l/a where area(a) is inversely proportional to resistance (R), so if (a) increases, R decreases & if R is less the leakage current will take low resistance path so the earth pin should be thicker. but in VCB the medium is vacuum gas. and p.t. 109. 63. Its Single Phase induction motor which mostly squirrel cage rotor and are capacitor start capacitor run. What is reverse power relay? Also, explain CMRR. Few advantages of storage batteries are mentioned below: 160. And air used as inHT breaker and air used as arc quenching medium in a motor! You are not flammable comes under power engineering with electrical engineering of 11kv and incomming feeder of 33kv and power! 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In parallel with the electric power for traction system ( i.e with job experience as maintenance Engineer interview questions the. Analogue or digital voltmeter, indicating frequency of equipment with job experience as maintenance Engineer related Frequently questions.
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