See for clearing ur basics u should have to concenrate on ur studies and read the chapters again and again.Learn the concepts by solving numericals.Imagine the situation given in the numerical and this will help u in making ur fundamentals clear.Learn by heart and keep ur mind open during reading and solving numericals.Numericals are the right way to study the physics. Sometimes the things has to be retain in the mind without thinking on them.So learn how to isolate those facts and try to focus on those fundamentals which can really help u alto in the exam and also valuable.All the best!!!!!