DRDO Interview Experience - BANGALORE, April 19, 2014
C: What is your life ambitions:
M: To work in any of the research field sir.
C: Tell me some of the research fields?
M: Isro, drdo. Barc.
C: As a B-Tech student if you get a software job with an initial pay of 50000 what can you do?
M: I don't want to leave my dream job sir.
C: Tell me your favourite subjects?
M: Edc. Stld along with microprocessors and controllers sir.
Member2: Distinguish b/w processor and controller?
M: Processor simply process where as controller in built contains processor.
Processor has multipurpose whereas controller has single purpose.
M2: No no I want to know exact difference (they want to confuse me).
M: Kept quiet for 30 seconds.
M2: Tell me what your project is about?
M2:What processor you used?
M: P89v51rd2 8051).
M2: 20 years back when I was doing my B.Tech I used same. You also used the same? Is there no other processor is available to you ?
M: No sir that processor and it is some what different in its config in terms of memory.
We had a good knowledge on it sir and recently we are switched to arm processors in this semester.
M1: Tell me about arm processor?
M: Yes sir its an high speed processor with >I million instructions per second.
It is rich in registers sir?
M1: It means?
M: It contains greater number of registers sir;.
M1: What is the benefit with registers?
M: Speed of operation is fast sir;.
M2: What are the specifications you see while purchasing an op amp?
M: I/p impedance, o/p impedance, cmrr, bias current.
No no you are missing some important.
M2: Have you ever listened the term slew rate?
M: Yes sir it's the rate of change of i/p voltage to o/p voltage (wrong) ?
Member2: Draw op amp symbol in inverting configuration and mention its gain?
M2: Why its called as inverting amplifier?
M: Because the input is given to the inverting terminal only its called as the inverting amplifier sir.
Is there any possibility is there to implement logic if there is no ic is available in market?
M: Yes sir we can, while I was doing my vhdl lab I written a code for 8: 1 mux and simulated it.
M2: What are universal logic gates?
M: Nand nor.
M2: Draw ex-or truth table?
Chairman: Can you write a logical expression for that?
M: Yes sir I can, a bar b + b bar a;.
What is fet:
M: Unijunction device sir with only majority carriers present only.
Chairman: Tell me types of fets?
M: Depletion mode and enhancement mode sir.
Draw their symbols?
Difference among them?
M: In depletion mode initially chanel present sir after proper voltage is applied the channel gets depleted sir, on applying full bias the total channel will cut off sir. Whereas In enhancement type initially there is no conduction channel present but on proper supply voltage the channel gets enhanced sir.
Member 3: Troubled me a lot with his low voice and want to damage my self confidence.
Can you explain me about the diode operation in detail?
Assume you are a teacher and I am a student I don't know anything about that?
M: Explained but he is not satisfied I think.
M3: Why the name diode came?
M: I don't know sir.
Draw symbol and tell me what a depletion layer contains?
M: Drawn and the depletion layer contains an immobile ions sir.
M3: What is intrinsic semiconductor?
M: Purest form of conductor.
M3: Asked in depth about 3 more silly and tough questions.
M: I had not given better answers but told up to 45%.
M3: Tell me what are pentavalent and trivalent impurities?
M: Pentavalent : Arsenic antimony phosphorous.
Trivalent: Boron gallium indium.