Important Technical questions for ESE EE interview

By Himanshu Bajpai|Updated : January 4th, 2022

UPSC ESE Mains Exam 2021 results have been announced on the official website, the link for which is UPSC carried the UPSC Engineering Services (Main) exam on November 21, 2021. UPSC ESE Mains Exam 2021 results have been announced on the official website, the link for which is Candidates who have successfully cleared the UPSC ESE Mains EE exam will directly be called for the personality test or interview round.ESE mains ESE EE exam is the most important part of the examination as it carries 200 marks and final selection can vary with marks of interview.

The Union Public Commission holds the Engineering Services Examination (ESE) EE in three stages. The first papers are written examinations, whereas the Personality Test is a one-on-one round. . Candidates qualifying Prelims and Mains have to appear for the Interview round for final selection.

  • IES Preliminary
  • IES Mains and
  • Interview/ Personality Test

Also, Check IES ESE Electrical Engineering Revision Tips 2021

Table of Content

Through IES, Electrical engineers can work under the Government of India in the following sectors:

  • Indian Railways,
  • Power Telecommunications,
  • Central water Engineering,
  • Defence service of Engineers,
  • Central Engineering services etc

Also, Check IES EE Syllabus 

UPSC ESE Important Date 2021

ESE 2021 Prelims Exam18th July 2021
ESE 2021 Prelims Result6th August 2021
ESE 2021 Mains Exam21st November 2021
ESE 2021 Mains Result22nd December 2021
ESE 2021 InterviewTo be notified later
ESE 2021 Final Merit ListTo be notified later

ESE IES 2021 Interview

  • For the personality test, candidates are selected from the Mains exam equal to twice the number of vacancies.
  • The total marks available for the personality test will be 200, with no minimum passing score.
  • Leadership, initiative, and intellectual curiosity, tact other social traits, mental and physical energy, practical application abilities, and character integrity will be evaluated as part of the personality test.

How to fill Detailed Application Form (DAF) for UPSC IES Interview?

Before filling the online Detailed Application Form, please read the following guidelines.

  • Candidates must complete and submit a detailed online application form at
  • Candidates must verify that all columns are completed correctly. The Commission will not respond to any correspondence sent to it.
  • Online DAF has SIX modules as
    • Personal
    • Educational Information
    • Parental Information
    • Employment Information,
    • Upload documents
    • Final Submission
  • Candidates are required to fill all the modules completely before finally submitting the Form ONLINE, using the Final Submission Module.

Important Technical questions for ESE EE interview

Candidates preparing for the interview round can check some important guidelines and questions asked in the IES interview in the following article.

  • What is transformer efficiency?
  • Can you compare the HVDC system to the HVAC system?
  • Can you develop a motor drive for us?
  • Compare AC with DC in applications?
  • Compare between autotransformer & single phase transformer?
  • Compare between thermal power plant & hydropower plant?
  • Compare three single-phase transformers with a three-phase transformer?
  • Define reciprocity theorem?
  • Define superposition & MPT theory?
  • Describe the process of lightning?
  • Difference between CFL &tube lights?
  • Difference between IGBT& GTO?
  • Difference between isolator and circuit breaker.
  • Difference between LCD & CRT?
  • Difference between LED and normal diode?
  • Difference between line commutation & load commutation?
  • Do you have any idea about the latest technology of IGBT based drives used in Indian railways?
  • Draw the equivalent diagram of the transformer?
  • Explain RLC filter?
  • Explain speed control of induction motor?
  • Explain the transients that occur in the power system.
  • Explain the working of the fan regulator?
  • Explain the working of a synchronous generator?
  • Explain the working of tunnel diodes?
  • For what value of ratio, arms ratio gives maximum Wheatstone bridge sensitivity?
  • Give examples of dependent & independent sources?
  • How a circuit is said to be linear?
  • How does a diesel engine work?
  • How does a railway collision device work?
  • How bourdon tube is used to measure pressure?
  • How do you check conductivity of gases?
  • How do you define resistance & resistivity?
  • How do you design an anti-theft car system?
  • How do you select base values in per unit calculation?
  • How does a motor drive sometimes cause the failure of motor windings?
  • How does the microwave works?
  • How does thyristor works?
  • How grounding is provided in METRO-rail?
  • How does induction motor work?
  • How power flow control is maintained?
  • How do solar panels work?
  • How to double the productivity of a turbine?
  • How to measure the temperature of oil in the transformer?
  • How to reduce distribution losses?
  • How to reduce magnetizing current.
  • How to select a modern fan or pump?
  • How voltage is generated in a spark plug?
  • Ideal OP-AMP & its characteristics?
  • Is the battery used in mobile phones is an active element?
  • Is a precise result guarantee to be accurate?
  • Is two wattmeter method is applicable for balance as well as unbalanced load?
  • Methods to improve the efficiency of a transformer?
  • On what factors power transfer capability of a transmission line depends?
  • Operating modes of 555 timers? explain anyone
  • Operation & its advantage of SF6 circuit breaker
  • Tell us about generator efficiency?
  • Tell us about methods of Transformer protection?
  • Tell us something about Hybrid cars?
  • Tell us something about maintenance
  • Tell us something about the PN junction diode & transistor?
  • Tell us something about wind/solar energy?
  • Type of insulation used in the motor?
  • what are copper losses?
  • What are the differences b/w independent & dependent sources?
  • What are the different types of faults in transmission lines?
  • What are the steps you will take before starting a generator?
  • What are the adjustments you will make for friction compensation in the energy meter?
  • What are the brushless alternators?
  • What are the constraints of electrical energy?
  • What are the different types of alternators?
  • What are the different types of cables & their specification used in electric power distribution?
  • What are the different types of insulation tests for a cable?
  • What are the different types of integrating instruments?
  • What are the different types of relays?
  • What are the different types of transducers?
  • What are the electrical aspects of generator design & Rotor design?
  • What is the equipment used in the switchyard?
  • What are the generating voltages?
  • What are the generators used for traction purposes?
  • What are the insulation classes?
  • What are the methods of alternator protection?
  • What are the methods of speed control of DC motors?
  • What are the problems encountered while measuring very low & very high resistances?
  • What are the protection zones of the distance protection scheme?
  • What is the specification of the 1200 KV line?
  • What are the tariff types in electric power distribution?
  • What are the types of amplifiers you learned?
  • What are the types of stability in power systems?
  • What are the uses of earthing switches?
  • What are the types of PCBs and their fabrication?
  • What are the types of rectifiers?
  • What charges the Earth?
  • What do you know about gas power stations?
  • What do you know about Voltmeter & Ammeter?
  • What do you mean by coupling capacitor?
  • What do you mean by a dry transformer and harmonic suppression?
  • What do you mean by the stability of a synchronous machine?
  • What do you understand by breaker lockout?
  • What do you understand by dielectric strength?
  • What do you understand by distance protection?
  • What do you understand by Energy auditing?
  • What do you understand by per unit impedance?
  • What do you understand by the rating AC in TON?
  • What do you understand by a stable system?
  • What is an active element?
  • What is an induction furnace?
  • What is armature reaction?
  • What is creeping in the energy meter?
  • What is the difference between lightning and surge arresters?
  • What is eddy current, how does it affect transformer performance?
  • What is ESLR?
  • What is lap & wave winding?
  • What is magneto-striction?
  • What is op-amp?
  • What is Peltier& Thomson effect?
  • What is Phantom Loading?
  • What is phase error in a Potential transformer?
  • What is a Power swing?
  • What is reactive power?
  • What is resonance?
  • What is Scott connection in a 3-phase transformer?
  • What is SDH?
  • What is the sliding balance effect in ac bridge balance and how to rectify this problem?
  • What is stability?
  • What is a surge arrester?
  • what is an asynchronous condenser?
  • What is the advantage of electro-dynamo type instruments?
  • What is the DC line voltage?
  • What is the dielectric strength?
  • What is the effect of armature reaction on generator field winding?
  • What is the effect of frequency & voltage variation on losses of Transformer?
  • What is the effect of turbine blade angle?
  • What is the importance of earthing in an electric circuit?
  • What is the importance of earthing instruments?
  • What is the importance of sub-stations in the power system?
  • What is the percentage efficiency of a thermal power plant?
  • What is the sensitivity of an instrument?
  • What is the significance of the air gap in the rotating machine?
  • What is the significance of load flows?
  • What is the significance of Surge impedance?
  • What type of relays and CBs will be used in the substation?
  • What do you know about base and peak load power plants?
  • What are the different types of winding in synchronous machines?
  • Which insulation is used in the electric cable?
  • Which motor do we use in paper industries?
  • Which one is large-signal and which one is small signal stability
  • Why control spring is not provided in the power factor meter?
  • Why double cage rotor is preferred over a wound rotor in an induction motor?
  • Why losses are more in Uttar Pradesh than in other states?
  • Why megger is used?
  • Why rotating disc of the energy meter is made of aluminium?
  • Why secondary of the Current transformer is never open-circuited?
  • Why silicon is used in the core of the transformer?
  • Why swamping resistance is made of manganin?
  • Why do we use stone on the railway track but not at the Metro rail track?
  • Write the equation of series resonance circuits?

If you are preparing for ESE/ GATE or other PSU Exams, then avail Online Classroom Program for ESE and GATE: 

Comprehensive Preparation for GATE & ESE EE

Attempt online mock tests of ESE & GATE 2022 at BYJU'S Exam Prep to improve the exam score in all disciplines.

Online Test Series for ESE and GATE EE

***BYJU'S Exam Prep wishes Best of luck to all the candidates who are selected in ESE Mains 2021| A Heartly Congratulations.***


All the Best


write a comment
Load Previous Comments

KiranJan 9, 2018

Don't send answers to any one .... We should try by reading the topics ....They might ask some  other questions from these topics...

RahulMay 13, 2018

Answer to
Please send this booklet with answers                                    

UmeshrajSep 5, 2018

Send these questions with answers to my mail sir.....
Pavan Kumar P
Pls  sir , send answers
Fathima samrin p
Sir, Could you please send this questions and answers to
Kaushal Kumar
Sir please send these questions and answer to
Nik Hill

Nik HillNov 15, 2019

Thankq so much
Krishna Gopal Raikwar
Please sir send questions  and answers


  • Previous year technical questions are important for finding your shortcomings or weaker areas in the technical portion.

  • ESE EE interview is conducted for 200 marks.

Follow us for latest updates