ESE 2021 Interview (Electronics and Telecommunication)Name : Vaibhav ChhabraDate : 14-Sept-2018Final Result : AIR 32Marks : 118/200 (I was expecting around 130 though)Chairman (CM) : Air Marshall A.S. Bhonsale ( Charming Gentlemen with a big smile , made me very comfortable)Technical Advisors : 2 females (F1, F2 ) and 1 male (M3) (All welcomed me with warm smile)Interview Duration - 28 minsInterview Transcript :Me : May I come in , wished all Good morning.CM : Have your seat .Me: Thank you sir. (All 4 panelists welcomed me with warm smiles , that made me less nervous)CM: How are you Vaibhav?Me: I am fine Sir , Thank you . How are you?CM : We all are fine ( with wide smile) . Seeing your DAF , you seem to be a suitable candidate and for next 20-25 mins we will ask you some questions and will check your Technical knowledge and general awareness. You can answer in English , Hindi , Mixed whatever is comfortable. Here is your note pad and pencil , you can use this for answering and this glass of water is for you.Shall we begin?* I feel CM is such a good personality and i became his fan just because of these initial; 3-4 minutes he spoke which broke the ice for conversation and made me very comfortable in that environment.Me: Yes , sir.CM : So your DAF seems interesting , you had teaching experience.Me : Yes sir , and explained where i worked.CM : And now you are working in BSNL as JTO.Me : Yes , sir.Cm : Oh , so you are about to complete one year on 25th sept , thats good.Me: Thank you sir.CM: Lets start with your hobbies. So you like cooking. I will give you a situation, If you have to invite 4 of us for lunch , then decide a menu and tell us the details.Me : Sir , i would like to know your preferences (I immediately started answering)CM: Dont hurry , take 10 seconds and think. This looks like an easy question , but its not that easy.Me: Thought for 10 secs and started telling menu.* This answer created a few light moments and all were smiling along with me. I feel CM was happy with my answer.CM : Lets start with technical. Have you studied RADAR in your curriculum?Me: Sorry sir , I am from Instrumentation and control background and i have not studied RADARS in my curriculum.* after which he looked at DAFCM: Oh , okay. So tell me difference between Analog systems and Digitals systems/Instruments.Me: explained him and mixed both english and hindiCM : benefits of Analog over digitala & digital over analog systemsMe: Answered him properly. I felt CM was satisfied and he signaled to F1.F1 : So , do you know differential amplifier. Draw it.Me : drawn and explained a bitF1: how is difference voltage is amplified here?Me : Thought for a while and said i cant recall , sorry.F1: Draw opamp inverting amplifier.Me: drawnF1: why gain is called inverting hereMe : explained and started proving mathematically as she asked me to. Used a word virtual short circuit. so she stopped meF1 : what is virtual ground?Me: explained , but she was not satisfied.F1: explain opamp's characteristics.Me: I made a plot and explained Linear and saturation region.F1: Why voltage in opamp saturates when it has such high gain.Me: Explained and she was satisfied.F1: applications of opamp?Me: told a few negetive feeedback based and positive feedback based and she asked for more.Me: I told flash type ADC and r-2R DACF1: what is flash type ADC , what is the benefit.Me: I explained components of flash type and told benefit of fastest ADCF1: Name few more ADCMe: Succesive approx and Ramp type.F1: explain SAR and which one better between SAR and flash type.Me : explainedF1: Disadvanatges of Flash type.Me: I couldnt recall anything , so i told it uses large number of resistors and Opamps , so for higher bits we can avoid using Flash type if speed of response is not the main criteria. I felt she was happy with the answer ( or may be i am very optimistic)Now F2 started , she was a bit aged and talked in very low volume , so had to ask question again 2-3 instances. I hope that wont affect my marks.F2: What is stability of a system.Me: Mam for any input transients must die out in a limited time,output must reach a steady state.F2: Tell names of some DAC.Me: R2R ladder , Weighted summerF2: how many clock cycles it needs at maximum for 3 bitsMe : told the answer .F2: which one is better among the two and why.Me: I said R-2R is better because we only need R and 2R throughout the circuit whereas in Weighted summer we need resistances in wide range.F2: for 3 bits tell me what all resistors you need in weighted summer.Me : I explained and she was convinced and helped me in answering also.* At this point i must tell you , just be confident in answering and if anything you dont know slow down and take time to think and they will help you . Dont answer incorrectly.I found my panel was very helping .F2: So you are from Instrumentation , tell me transducers used for pressureMe: I named almost 7-8. She was smiling.F2: Transducers for Level measurement.Me: Mam simplest is float level measurement.F2: why simplest , where it is used.Me: I explained mechanism a bit and told its used in water tanks and flush tanks. She was satisfied.Me: Then i said if liquid is dielectric , we can use cylindrical capacitance Level measurement.F2: she told to explain.Me: Mam , may i use sheet for explaining , she nodded and i explained with proper diagram and general principle.F2: any condition on liquid used in this method?Me : Yes mam , it should not be conducting otherwise short circuit will occur. liquid must be dielectric.I felt she was happy with my last answer and passed on to M3M3: What is intrumentation amplifier and is what is special about it.Me : I explained Intrumentation amplifier in short.Sir , Special thing in Instrumentation amplifer is that it has 2 voltage buffers using opamps connected to bridge output which prevents current from leaking out of the bridge.M3: What is it called.Me: Sir , loading effect.* This gentleman also had warm smiles after all my answers. He had a very nice appreciating tone and gesture after each correct answer that impressed him.M3: What is the problem when loading effect occurs?Me: Sir , accuracy of measurement is compromised and explained referring bridge and galvanometer readings.M3: We use industrial tranducers , those output signals are strong for direct processing?Me: Sir , not always. In cases of weak output we need to amplify signals using signal conditioning circuits.M3: Good , so in which department of BSNL you are posted.Me: Sir , enterprise business of NCR-1 unit.M3: BSNL must have given training .Me: yes sir.M3: where?Me: Rajpura , PunjabM3: What did you study in your training.Me: I told names of subjects.* Here i would like to tell you that i mentioned only those topics which i revised so that he asks me from that only and this only happened. He started asking me from the 2nd topic i mentioned.M3: What is full form of MPLS.M3: What is its benefit?M3: What is leased line network?M3: Why enterprise customers dont use broadband and take MPLS?M3: How it is different from point to point leased line?M3: Explain mechanism in MPLS , you can use paper pencil.M3: What is VPN tunnel ( didnt have much idea about it but answered using VPN knowledge and he seemed satisfied)M3: So we can say VPN is a premium service.* I answered almost all the questions regarding work profile in JTO , BSNL ( Fully correct or not , I am not sure but M3 seemed to be satisfied most of the time.)Finally , Chairman started looking at me with a wide smile for a pause of 6-7 seconds and said nothing and i coudnt help but smiled back.CM: Satisfied?Me: Yes , sir?CM : Fully satisfied ya aur kasar baaki hai? ( I laughed a bit with all four panelists )Me: No sir (with wide smile)CM : Okay , so thank you.Me : Thank you sir (looking only towards CM , I forgot to say thank you to all other members but smiled to all before leaving)I enjoyed the whole interview and those 28 minutes passed with speed of light.All the best ESE aspirants.Below is link for my Interview with made easy where i shared my ESE Journey.I hope this video motivates you for all your future ventures.