One the great thing about OURAeSI group, that aims to unite all the members of AeSI, is that the spirit of community is there and people share their experiences.Back in 2003 tejas patel gave DRDO SET examination and passed it. After that he had his DRDO technical interview. Every one has that, what special about it?
After that he was generous enough to share his experience with us in the ouraesi club. Since the number of messages in yahoo groups gets buried under the layers of many messages, i am pasting it here with my remarks at the end so that they will from hence forth available via google search and can benefit more people.
Tejas patel wrote:
this is for the idea of the friends who r doing aesi.
my interview was on 1st of dec.
there were 13 guys who had came for the interview.
i dont know, but some of the people were saying that
they have called on the merit of written test--SET
2003.
the first 3(i.e.1st,2nd and 3rd of dec) days were for
general candidates followed by 2 days for obc's and
last one for obc and sc/st's.
for the kind information out of 13 present there 7
were from ganesh institute!(i.e.more than 50% to
say).namely in the order of calling,Tejas,Praveen
Bajpai,Puneet Gupta,Prashant Jha,Darshan Trivedi,Suraj
Chaurasia and Sinder.If any body of above persons
spelling if written wrong then its by mistake only.
My interview was more of a sort of introduction then
q&a.
during my interview there were 5 interviewers.2 were
IISc bangalore's professors.one was head
GTRE,bangalore.one was of DRDO lab in agra(i dont know
which).the chairman was from REC warangal.
the rest of the talk i will indicate who asked what.
the next some initial questions from chairman.
Chairman:first question was u have done ur aesi,where
u working while studying?
myself: no
C:then did u prepared ur self?
M:no.
C:then did u took guidance from somewhere?
M:i said yes.
C:where?
M:Ganesh Institute ,Chennai.
(for the next coming candidates he himself asked u r
also from ganesh institute?)
C:u havent done any practical.?
M:yes
C:where?
M:iit madras.
C:u r in first semester , u have 3 more semesters.out
of which 2 are practical.how will u join here?
M:i will request u to give me time to complete,or i
will take a break from m.tech and join here or i will
shift my project in drdo and complete the M.tech.
C:What if i dont give u time to complete the M.tech?
M:I will request u to give me time......
C:what shall i ask?
C:have u seen any wind tunnels?
M:yes.
C:where?
M:iit madras.
C:what type?
M:all the three subsonic,transonic and supersonic.
C:what is the test section range of supersonic
windtunnel in iit madras?
M:mach 2-2.5.(it depends,but to less complicate the
matters i gave this number)
C:wht is the area of the test section?
M:(i couldnt recall exactlyso i said )100mm*100mm.
then the professor from IISc took over.
Prof:which is ur favourite subject?
M:Gas dynamics
P:Ok.i ask u one question.
M:OK.
P:design a mach 3 supersonic cruise missile,with nose
l/d ratio of 1,middle lifting surface of l/d 10 and
tail lifting surface of l/d 5.
(I was quite confused to hear so high question )
M:is it blunt nose?
P:yes
(here i make a mistake)
M:this is missile why do u want to have lifting
surface?
ALL:that u decide u have to design.
(I showed something which was a missile but i dont
know whether it was what he was asking or something
different.but i suppose he wanted that only because he
didnt gave any comment)
P:show me the shock pattern.
(again i was confused what to do,what we have studied
is only bow shock and rest we dont know what happens
at back)
(Still drew something,he didnt commented so i
suppose..)
P:show me the location of CP?
M:give me the freestream pressure.
P:just tell me by ur idea where it will lie.
M:between mid and tail section.
P:why ?
M:because we are having shock (some explanation i gave
on paper by drawing ,and he was not satisfied)
P:OK,if i give u three CP's of nose,midsection and
tail section.can u find CP.
(I was thinking to tell him to say what we do in CMcg
way.that at cp the moment wont come.)
P:i dont want explanation.
M:yes
P:how?
(b4 i say something)
P:my last hint (zigma M/zigma L)
(b4 i start my word)
P:i dont want explanation.just tell me.
(b4 i start)
C:Ok leave it.
another prof of IISc.
P2:what is stress concentration factor?
(i had heard something like that but i couldnt recall
so i gave bluff)
M:max stress by average stress.
P2:draw an rectangular element,make a hole in
that,apply a tension load.
P2:where will be the max stress?
(b4 i can put my pencil on paper)
P2:on the edges of the circle?
M:yes.
P2:ok,u must have learned theory of elasticity.take an
element from that rectangular element.show me the
stress pattern.
(I showed something ,OK.I also know that it was wrong
but i was off by the missile question)
then came GTRE head:(he asked a simple question and i
made mistake)
G:take a rod and apply bending and torsion
simultaneous ly.what will be bending moment diagram?
G:will it be direct addition or direct subtraction?
M:its addition(that's my mistake)
G:direct?
M:no,some equivalent value.(i couldnt recall the
formula there which i would have dont atleast 100
times)
then came the agra heads turn
A:so u have seen the wind tunnel,what we do in wind
tunnel?
M:we test the model
A:how we will test,directly i can take a model and
test there?
M:no there should be dynamic similarity.(at that time
it could not recall kinematic similarity)
A:what will u equate?
M:reynolds no,and mach no in our cased.
A:and ..?
M:Froude no,but we dont give much preferrence to it.
A:that's what i wanted.
A:how will i test a LCA,if i have particular reynolds
no then how will u test it in wind tunnel?
M:we will match the reynolds no.
A:how?
M:suppose u have a one fifth model then vary other
parameters so that it remains same.
A:OK
then again it came with chairman.
C:u say u have worked on supersonic WT.
C:why dont we dont equate reynolds no there?
M:at high speed mach no i similarity is more important
than reynolds no similarity.
(this is probably the wrong answer)
C:ok if i want to increase the test section mach no
what should i do?
M:increase the area ratio.
C:will that be sufficient ?
M:other consideration will be the pressure,either
increase the total pressure or decrease the back
pressure.
C:ok what is area ratio?
M(I explained that)
C:what is throat area?
(i explained that also)
C:so can i increase the area in any way i like?
M :no
C:what if i put a cone?will it give me increase in
mach no?
M:no,it will have to be carefully designed
C:why?
M:otherwise that wont give isentropic flow.
C:have u heard about method of characteristics?
M:yes but i have not applied any where.
C:OK,thank u,u can go.
i know i had made lot of mistakes but this was my
first technical interview.so i am happy even if i dont
get it.i tried to perform well,but was baffled with
the first question.
any way the above is for others information so they
dont make mistakes.
tejas.
so this is the post of tejas, i have intentionally left the message intact to give you the flavor of the sitution there. First of all thanks to tejas for the candid and honest mail about the interview.
As mentioned in the earlier post, look from where most of the questions were triggered..
The fav subject is omni present and this is where the whole interview got its focus. See how different it would have been if the question tejas's answer was more related to a subject he knew a lot about. So the first lessons to learn is have your favorite subject ready. Let it be the subject that you know the most about and the subjects in which you are most confident.
Second thing that you might have noticed is that all other questions that are asked are from the replies that tejas was giving, so you see interviewee is the one who leads the interview. It is your words that triggers the questions, so keep them to the territories that is topics that you are confident about.
Since this is already a long post i'll discuss other points in some other post.
