i have bought physics corrwspondence course from askiitians....... plz suggest me how i prepare for it . ........... i have a good understanding in physics most part. but face little difficulties in sound waves , wave optics, emi , ac and electromagnetishm..... ihow i prepare fo this topic to strenthen my concept.... also how i prepare for other physics topic to become more strong at that topic................. and plz tell me how i become very strong and attempt any type of question in callculas part.............. and also in organic chemistry....... plz help because im damm serious about this matter .............. i am a dropper ........plz help..................