1. how many years does it take to complete pHD in US
Ans. Average is 3 to 5yrs usually but it may be more in some Ivy league schools.
2.i had qualified for NET JRF exam to pursue pHD in India but failed to get a good lab..hence one year was wasted. how do i justify the gap in my studies while applying.
Just dont mention.
3. i dont have a research paper in masters..does that reduce my chances for being consideres for pHD?
Basically, papers are a plus in application. But if you dont have its ok. You should get a good GRE and TOEFL with very good letter of recommendation and nicely written statement of purpose.
4. how should i shortlist the universities.. that is how do i select from the loads of information available on the net.
First give your GRE bcoz good schools need a high GRE scores so if you have that then check ranking at www.usnews.com you can find more university at www.gradschools.com