Interview questions for EEE
1. Why star delta starter is preferred with induction motor?
Star delta starter is preferred with induction motor due to following reasons:
• Starting current is reduced 3-4 times of the direct current due to which voltage drops and hence it causes less losses.
• Star delta starter circuit comes in circuit first during starting of motor, which reduces voltage 3 times, that is why current also reduces up to 3 times and hence less motor burning is caused.
• In addition, starting torque is increased and it prevents the damage of motor winding.
2. What is meant by Reactor in power system and what are the uses?
when a transmission line of EHV is charged at no load, the charging current flow between all phases will create a capacitive effect, resulting the receiving end voltage become more than sending end voltage.Reactors which have very high self inductance and negligible resistance. stabilize the receiving end voltage.
3. State the difference between generator and alternator?
Generator and alternator are two devices, which converts mechanical energy into electrical energy. Both have the same principle of electromagnetic induction, the only difference is that their construction. Generator persists stationary magnetic field and rotating conductor which rolls on the armature with slip rings and brushes riding against each other, hence it converts the induced emf into dc current for external load whereas an alternator has a stationary armature and rotating magnetic field for high voltages but for low voltage output rotating armature and stationary magnetic field is used.
4. What would you claim to be your speciality within your core field?
Another variation of this particular question can be – ‘which engineering are you good at; industrial, residential or any other?’
This is one of the common interview questions often asked from engineering freshers. A great way to answer it would be to talk about the internships and the projects you have done in the past. Which industry or field you are particularly good at; all the while making it clear that you are not a noob in other niches.
You need to rely on your expertise to sail you through this particular question. Also, answer the question tactfully and play to your strengths under all circumstances.
5. Why AC systems are preferred over DC systems?
Due to following reasons, AC systems are preferred over DC systems:
a. It is easy to maintain and change the voltage of AC electricity for transmission and distribution.
b. Plant cost for AC transmission (circuit breakers, transformers etc) is much lower than the equivalent DC transmission
c. From power stations, AC is produced so it is better to use AC then DC instead of converting it.
d. When a large fault occurs in a network, it is easier to interrupt in an AC system, as the sine wave current will naturally tend to zero at some point making the current easier to interrupt.
6. Explain about an electrical issue which you solved on your own?(during any of your projects or internships or otherwise).
A person who can be a problem solver will be a great addition to the team and company. And, therefore, you need to grab on this opportunity to prove to the recruiter that you are THE IDEAL CANDIDATE.
However, making up a situation won’t really cut it. So, be honest in your approach and pick up real examples. Talk about the problem you faced, the steps you took to overcome it and the end result.
7. How can you relate power engineering with electrical engineering?
Power engineering is a sub division of electrical engineering. It deals with generation, transmission and distribution of energy in electrical form. Design of all power equipments also comes under power engineering. Power engineers may work on the design and maintenance of the power grid i.e. called on grid systems and they might work on off grid systems that are not connected to the system.
8. What would you do if not electrical engineering?
However, the smart way to not answer this question would be to tell the recruiter you would have settled for another branch.
Saying that will make you sound like a person with some unfulfilled desires who is probably not happy in the field he is currently in. Instead, say that you would have been in a field that reflects the values of electrical engineering – something like Power Engineering.
Keep it in mind that you should be able to justify your interest and passion in this field at any given time during the job interview.
9. What are the various kind of cables used for transmission?
Cables, which are used for transmitting power, can be categorized in three forms:
• Low-tension cables, which can transmit voltage upto 1000 volts.
• High-tension cables can transmit voltage upto 23000 volts.
• Super tension cables can transmit voltage 66 kV to 132 kV.
10. Do you think there’s any direct link between power engineering and electrical engineering? If yes, then what is it?
In fact, you need to keep it in mind that every engineering field connects with other in some way or the other and no engineering field is particularly independent.
While you might not be confronted with this particular question during your fresher interview, it doesn’t mean that you won’t be asked similar questions.
To answer such technical interview questions, you should relax, think over the question carefully and then come up with an answer. Even if your answer is not really correct or not exactly what the interviewer is looking for, they will still appreciate you if you put in some effort and try to use your knowledge of the subject to try and come up with an answer.
11. Explain the application of storage batteries?
Storage batteries are used for various purposes, some of the applications are mentioned below:
• For the operation of protective devices and for emergency lighting at generating stations and substations.
• For starting, ignition and lighting of automobiles, aircrafts etc.
• For lighting on steam and diesel railways trains.
• As a supply power source in telephone exchange, laboratories and broad casting stations.
• For emergency lighting at hospitals, banks, rural areas where electricity supplies are not possible.