Ability to solve the conceptual problems comes from the practice and the indepth knowlegde of the topics that has been asked.The conceptual problems generally asked in any exam can be prepared best by having the look at the previous year paper .In which you can specifically look for same topics questions.There would be the little change in the concept when they ask the same topics in JEE.This pattern is generally observed in Competitve Exams

All the Best

Shubham Goel(DTU)