Form I1 34: Fill & Download for Free

I've already written an answer on similar lines. I'm putting up the same answer here as well- dated 11th Nov 2017.I got selected yesterday for the post.A little background- I graduated from BITS-Pilani, Hyderabad campus with degrees in M.Sc Mathematics And B.E Mechanical Engineering in 2016 and I was preparing for ESE and GATE 2017 without any job in hand. I didn't even sit for placements because I wasn't interested in IT nor was I interested in Analytics. I wanted to be in Core which I was sure I wouldn't get into with the knowledge I had when I graduated.About my Selection procedure- I applied for the exam in February 2017, I wrote the exam on may 05th 2017, my interview was on oct 9th in Chennai's ISRO guest house, pallavaram, I got the selection results on 10th Nov 2017. I scored 142 in the written exam for which the cut off was 139. About 310 people were asked to attend the interview, 34 people were selected this year, my interview score was 71 out of 100 and I stood in the 17th position on the panel.I was asked to report on 9th October at 8am in the guest house for the interview, I went there at 7:30. they checked my certificates and mark sheets and we were then given breakfast. My interview started at 10:30 am and lasted for about 20 minutes. There were about 8–9 people on the panel with a lady in the center whom I'm guessing was the HR. This is a more or less accurate transcript of what happened during my interview-*entered wishing everyone good morning with a smile and I was asked to sit, I did*I1: good morning Pranay, tell me a bit about yourself.M: My name is Pranay, I graduated from BITS-Pilani in 2016 with degrees in Mathematics and Mechanical engineering.I1: (interrupting) BITS-Pilani? Hyderabad Campus?M: yes Sir, Hyderabad CampusI1: Is there anything you’d like to say more? (I was trying to say I have 6 months of experience in design of solar trackers and a bit of teaching experience, he didn't kind of let me. he rushed through)I1: so, what have you been doing since?M: Sir, I was preparing for IES, GATE, ISRO.I1: oh, Did you take coaching?M: yes sir.I1: where?M: Sir, Ace Engineering Academy, Hyderabad.I1: okay, tell me your favorite subjects.M: sir, Mechanics of Solids and Basics of Thermodynamics (these were my only favorites)I1: tell me more..M: Heat and Mass transfer.I1: tell me one more…M: ( had to think and nothing came to my mind) ummm sir, fluid Mechanics ( I hate Fluid mechanics but I couldn't remember any other subject’s name lol)I1: okay. ( notes it down and Prompts an other person on my right extreme to start, he seemed like an expert in rocket propulsion)I2: okay Pranay, do you know the laws of thermodynamics? can you tell us a bit about them..M: yes sir, ( I thought for a second and composed my answer in my head) There are 4 laws of thermodynamics, the zeroth law talks about thermal equilibrium and gives us an idea about the quantity temperature, the first law is conservation of energy with respect to thermodynamic cycles, the second law talks about the possibility of processes or cycles, there are actually two statements for this law, one is the kelvin-plank statement and the other is the clausius statement, the third law talks about the possibility of attaining zero kelvin and it isn't possible without infinite cycles.I3: oh so you’re saying a cycle is possible or not, by what do you decide if it’s possible?M: sir entropy is the quantity by which we decide if the cycle is possible or not. if the net entropy generated in a cycle is positive or zero only then the cycle is possible.I3: what is entropy?M: ( I don't know the definition) Sir entropy can be a property of a substance, it can be generated in a process or a cycle..I3: but I still don't understand entropyM: (remembered) Sir its the order of disorder in a substance.I3: (smiling) Order of disorder.. hmmmM: sorry it’s the measure of disorder in a substance (then I smiled at my own stupidity, everyone else is smiling)I2: Please derive Cp - Cv=R on the board.M: Sir, for Ideal Gasses?I2:yes, ideal gasses.(got up, went to the board and my hands were trembling) then I wrote H=EnthalpyI2: don't write what they are, we know..M: ok.Wrote H=U+PVthen from H=Cp TU=Cv T & PV= R Tthen said therefore Cp= Cv + RI2: hmm.. What’s choked Flow?M: (drew convergent- divergent nozzle on the board) Sir, the type of flow in a nozzle where no more mass flow takes place even with the decrease in back pressure is called choked flow.I2: what’s the velocity at the smallest cross section in the choked flow?M: Mach 1.I2: ok.. why doesn't the mass flow increase even with decreasing back pressure?M: ( I had no idea, it was a deep question. I recollected all formulae and was trying to figure out in my head why and I realized it’ll take me time to figure it out) I’m not sure why sir. ( I could have said anything, like the critical pressure ratio has reached or drawn the mass flow rate vs back pressure ratio graph to beat around the bush and maybe I should have done that. but I didn't )I4: What is newton’s law of viscosity?M: (wrote formula on board while explaining) Sir according to newton's law of viscosity, in a laminar flow, the shear stress on a layer is directly proportional to the shear strain rate of that particular layer. and the constant of proportionality is called the coefficient of viscosity which is ideally a property of the material only.I4: What are the types of viscosity?M: there are two types, kinematic and dynamic viscosities. The dynamic viscosity divided by the density gives us the kinematic viscosity. Dynamic viscosity gives us an idea about the forces or momentum transfer between the layers whereas the kinematic viscosity gives us an idea about the velocity gradients between the layers.I4: Have you Heard about stoke and poise?M: (was confused if they’re asking about the people or the units but decided to go for units) Sir they’re the units of viscosity ( but I wasn't sure which one is for which type of viscosity, he looked a bit disappointed)I5: Can you tell us a bit about fits and tolerances?M:(thinking-Oh shit. I’m very bad at production and I was afraid of this moment. my face looked so confused. I looked as if I've never heard of the terms before, then I decided to tell whatever I know and I drew hole-shaft assembly tolerance grade graph) assembly of hole and shaft is given by these tolerance grades on the diagram here.I5: no I'm asking about the types of fits.M: (realized he’s talking about the 3 different fits) Oh, sir, there are 3 different fits of holes and shafts, clearance, interference and there is an other type of fit which I cant recollect the name of. (drew diagram of clearance fit correctly, drew diagram of interference fit wrong and I explained it as transition fit with full confidence.)I1: Which assembly type do we use?M: Sir we usually use hole based assembly.I1: why?M: that's because holes are harder to manufacture than shafts and we have standardized drill bits, so it makes sense for us to use hole based assembly.I1: ok good.I5: so will the hole and shaft always fit in interference fit?M: no sir, it’s like saying it may or it may not fit. while the third type of fit is like saying it will definitely not fit (this was a wrong statement because the third fit is interference fit)I5: what are composites and how are they different from alloys?M: composites are materials usually stuck together whereas alloys are melted and mixed together. (didn't know how to explain it better)I5: oh so composites are sticking together always?M: (no idea what to say) Bronze, Steels and Brass are examples of alloys whereas RCC structures, Kevlar and carbon fiber are composites.I6: What are the different theories of failure?M: Sir there are 5 theories of failureI6: (interrupting) only 5?M: (immediately) That I know of.. (I said this because there is always something which you wouldn't know. These people might be knowing more advanced theories to predict failure of advanced materials)I6: ok, what are they?M: Sir, Maximum Normal Stress Theory, Maximum Shear Stress Theory, Maximum Normal Strain theory, Maximum Strain Energy Theory & Maximum Shear Strain Energy theory.I6: What theory will you use for cast iron?M: cast iron is a brittle material. So I’ll use ……Maximum Shear Stress theory ( My stupid brain didn't work. It was maximum Normal Stress theory and I regretted this only moments later after the next question)I5: What are the different methods to join metals?M: Welding, riveting, bolting.I5: How do you decide how much torque is required for a bolt? And What is torque?M: (drew a bolt on the board and explained) The force multiplied by the perpendicular distance is torque and it tends to cause an angular acceleration. In case of a Bolt, The initial tightening torque depends on how much of stress we want to induce In the bolts and the coefficient of friction between the bolts, threads and the bolt head and the base. tightening torque is the sum of both these torques at threads and the head.I6: do you know Saint Venant’s Principle?M: I’m not sure what it is sir, but I do know a failure theory that is referenced by his name. I don't know which one though. I think its the maximum Normal strain theory.I6: no I'm asking about the St Venant’s principle. Without this you cant solve any mechanics problems..M: (I realized this was something very basic and I don't know it so tried shifting focus to theories of failure) I don't know sir, but St venant’s theory of failure is there but.I6: (puts his finger on the top of the glass in front of him) I’m applying force here. what’s gonna happen somewhere in between in the glass?M: sir compressive stresses are generated.I6: No, what will happen to the glass at this point? what will happen at the base?M: (now i’m like, Please leave it, I don't know what you’re talking about and I don't want to embarrass myself trying to get it right) Sir….. Compressive Stresses are generated.I6 gives up. I was happy. lol.I7:(The lady, Maybe the HR) Pranay, do you know any other countries that launched satellites or maybe have their launch vehicles?M: (understood that my interview has almost ended and that only 2 or 3 more questions will follow) yes ma’am, china, Russia, Europe’s ESA although not a country, and USA.I7: okay, What do you know about NASA?was going to answer but I1 changed the question to-I1: what is the full form of NASA?M:(thinking the original question was better. I didn't know the full form but I knew it started with National…) uhh… Sir I think it’s National… Something..I1: what?M: Sir I Know ESA is European Space Agency, so I'm guessing SA in NASA will also be Space Agency.I3: (with a lot of interest) Oh so what’s NA?M: (proceeding with my stupid logic in spite of knowing it’s wrong) Sir maybe it’s North American (with a puzzled look)I3 looked so satisfied with my answer. he looked at me like I gave the most correct answer in the whole world. Even I was surprised and thinking- What? Am I right? lol.I7: What’s newton’s law of gravitation?M: According to newton’s law of gravity, The force of attraction between two celestial objects is directly proportional to their individual masses and inversely proportional to the square of the distances between them.I7: hmm do you remember the value of the constant G?M: (I Didn't. and I cursed my fate) No ma’am, but I know it’s a very small value. I think it’s in the order of ten power minus 19. (it’s 6.673x10^-11 btw)I7: Thank you Pranay, you can Leave now.M: Thank you, Have a great day.Came out and told my mom that I messed up the interview. she scolded me very much because I didn't know the full form of NASA and the value of G.So, overall, it didn't go that good according to me. but I guess it was sufficient. They asked the very basics and not at all into depths. It was a fun interview, the panel was very friendly, I lost my fear after a couple of minutes into the interview.btw, they didn't ask me anything about my project. I was worried that they’d go into the Depths so I almost did my whole project again to know everything about it, and I also learnt a couple of advanced mechanics concepts in Master’s level just to try and impress them. but the interview just didn't proceed in thay direction.I have an international research paper with a couple of scientists from ISRO by the way, I attached that paper as well. But It wasn't on mechanical, it was more CS related on geographical mapping from 2D to 3D applications. Nobody took notice about it in the interview.So you can expect easy questions and friendly interviewers. I feel like I screwed up the interview but luckily, I didn't.Cheers.

Poland has the highest percentage of haplotype R1a, the Slavic gene, at 57%, Belarus second at 51% and Russia and Ukraine share third place with around 45%. The R1a haplotype was the major Y chromosome group in what was known as the Ukrainian Refuge, one of the several areas that existed up until the end of the last Ice Age where humans were able to survive the harsh weather conditions of the period. as the ice sheet move northwards so the people followed fanning out North, West and East.Mention has been made in some of the other answers in this thread of the surprising diversity of the German gene pool. When one considers the general intellectual hysteria that persisted in the Nineteenth and early Twentieth Century about racial purity usually in the German or Scandinavian domain, the modern scientific results in genetic profiling have proved ironic indeed. How could they have got it so wrong?To get a vague answer to this one must scrutinize a little more deeply into the general gene pool that is Europe.There were three other main refuge areas in Europe at the time. Iberia, Italy and the Balkans. Iberia was the main outpost of the R1b group the largest Y chromosome haplogroup in Europe. It is the largest group in all countries between Portugal in the west to Germany going east and from Italy in the south to the British Isles in the north but not in the Scandinavian lands. So what does that all mean?Well, what about Germany? The largest haplogroup is R1b, as mentioned, at around 45%, second are the Balkan groups, I1 and the I2, totalling 22%, R1a comes out at a whopping 16% and then there is a cluster of around 16% of Greco-Anatolian-Middle Eastern genes from the Neolithic - ie. not modern migrants.Germanic, Slavonic, Celtic, Greek, Italic & etc are all Indo-European Languages that began spreading throughout Europe around 10.000 years ago. The process started with the Neolithic farming revolution introduced by people from Anatolia, modern Turkey, who would have spoken an early proto-Indo-European tongue.It's pretty obvious that the first lot would have tumbled into the Balkans and made their way around the Black Sea and taught R1a their farming techniques and encouraged them to speak Indo-European, the Slavic version.Another lot would have ventured north, up the Danube and founded the first, rudimentary Germanic group of speakers. It is believed among this group were significant number of the I1, Balkan haplogroup. And yet, only 16% of modern German males belong to this group. Why?It is the result of Geography, anthropology as well as Linguistics.The Neolithic farmers did not reach Iberia until some 500 or more years after they had started spreading out into the Balkans. When they did finally get to Iberia they started a new branch of Indo-European which became known as Celtic. So by time the first R1b had spread out from Iberia into Northern Europe and into what we now know as Germany they would still be speaking Basque or an Iberian tongue, Celtic and the first Neolithic settlers still hadn't arrived in the peninsula.In the early days following the retreat of the last Ice age the expanding populations were still speaking in their native pre-Indo-European speech. There was a kind of pincer movement into Germany. The Balkan groups moved northwest and the Iberian group, R1b, moved north east. What sort of reception they gave one another we'll never know but in time, with the arrival of the first farmers from the Balkans, Germanic speech will have started evolving, replacing all local pre-Indo-European dialects.So, R1a is the Slavic Y chromosome haplogroup, R1b, the Celtic. Germanic is a difficult one to source.Of equal interest are the Scandinavian profiles.Sweden, 37%, I1; 16% R1a, and 22% R1b.Norway, 32%, I1; 25% R1a, and 32% R1b.Denmark, 34%, I1; 15% R1a, and 33%R1b.I mention Scandinavia because many of the Victorian era and early 20th century books I've read on this subject wrote of a pure or nearly pure Nordic race still existing in parts of Scandinavia. Admittedly, the haplogroup I1 is known as the Nordic gene and as the Germanic gene but this sort of information was unavailable back then. A quick look at the three main haplogroups that make up the Scandinavian lands show that they are anything but pure, however.It is fairly understandable why this kind of thinking went on back then. There are a large percentage of fair, blue eyed people in the I1 group and it is known that the group had in early times settled around that area on the north west coast of the Black Sea where the first blue eyed people had emerged and had multiplied by a practice of domestic selection. It is also thought that it was from this group and from this area that the first Proto-Germanic speakers began moving northward toward the region we now call Germany. But there was never a pure Nordic group. The spread of this pigmentation was contrived by a process of domestic selection beginning some 9 to 10 thousand years ago which spread into and overlapped other genetic groups as we witness today throughout Europe.

Slavic is not a race. It is a language. Slavic peoples are a mixed race of different peoples who happen to speak Slavic. Czechs are Slavic because of their language.Czechs are very interesting to study. They are the only Slavic people who are not “pure Slavic” by DNA. Roughly speaking Czechs have 30% R1a BUT it is not Z 280. Z 280 is found mostly in regions comprising of Poland, Belorussia, Russia, and Ukraine. Czechs have M 458 and some Z 283 which is shared with Germans. M 458 is a western R1a marker, which means that it mutated to Z 283 and Z 284 during the Corded Ware Era, which the Nordic peoples of Germany and Scandinavia possess.Czechs occupied a region that used to be Celtic (Boii) and later Germanic (Marcomannii and Quadii). So their R1b would most likely come from the Boii and I1 and R1b from the Marcomanni and Quadii. The Boii were expelled by the Germanic tribes and the Marcomanni and Quadii migrated west during the 5th century. But it is clear that some Celts and Germans stayed and mixed with the Czechs and adopted their language.Modern DNA of Czechs is as follows: I1 = 16%, I2a = 8%, R1a = 34%, R1b = 21%. I1, R1b and I2a = 45%. So almost half of Czech DNA is western (Celtic-German). The R1a (34%) is not Eastern Slavic so they are different from Poles, Russians and Ukrainians as well.So here is a case where a people (Czechs) borrowed or adopted a language from an invading people who were actually a minority (as far as DNA is concerned). Even though Czechs have more Celtic-Germanic DNA, they adopted the Slavic language probably because the Celtic and Germanic farmers had lost their leaders or were abandoned and had no choice but to adopt the language of Slavic speaking invaders.