First of all you have to be prepared with the three main sections those are verbal ability (English), quantitative aptitude, logical reasoning.
always keep one thing in mind that the online test is adaptive and it gets more tougher after uh solve every single question correctly.
the three sections were:
verbal ability- 25 questions (25 min)
quantitative aptitude-16 questions (16 min)
logical reasoning- 14 questions (14 min)
after clearing the online test, The very first round which you have to face is the technical interview round.
i appeared for the campus drive which took place at lnct bhopal on 19 sept 2014.
in technical round be prepared with your brach core subjects, weather you are from the non i.t brach you should have a good knowledge about your subjects and simultaneously you should also have a title knowledge about i.t as well.
i am from the electrical branch, so i was asked the questions regarding my field.
1. tell me something about yourself
2.oohh, so you are from a non it branch and still you have a inclination towards i.t company, why so ( if uh are from non i.t, so you have to be prepare for answering this often asked question at least)
3. tell me something new happening in your field regarding automation. (i told him about plc and scada)
4. tell me about your project
5.why in kV (kilo volt) k is written small and V is denoted by capital letter.(because v stands for volt and volt is a name of a scientist, whereas kilo is a quantity)
6.tell me the complete process and connection how the electricity reaches our switch board.
7.write a program for febonache series.
8. what is dbms
9.software development life cycle
10. which cell phone do you use, and on which platform it runs, and tell me what changes you have made in your android, being a technical student. (told)
11. on which os an android is made
12. tell me something about android 1
my technical interview lasted for 45 min, and it was a healthy conversation, you just have to be confident with what you say, you don't have to justify yourself every time, show him that you have a good learning capability, tell him about your extra curricular activities. And always wear a smile while making conversation with him.
if you clear your technical interview you will be called for the h.r round.
But once you clear the technical round be sure that you have crossed 90 % of the hurdle.
my hr interview went like this:
1. so how are you feeling
2. what you did since morning
3. what you had in your breakfast today.
4.tell me something about you.
5. hobbies
6. weakness
7 what is the difference between the innovation and the creativity.
8. are you flexible to relocate to any city
9. i am done now, if you want to ask something you can ask ( always ask one question, and that too not a silly one, ask him a sensible question)

just a key to success is your confidence and good communication skills, that's it. and rest is you luck.
all together 1600 students applied for the online test among those 450 were shortlisted for interviews, finally they selected 280, keep this thing in mind that cognizant is a mass recruiter, give your best short.

I was selected, good luck aspirants