U should totally focus on revising derivations now..Bcz there will be 5 marks questions where u will be given 3 marks for derivation and other 2 marks for a simple numerical..U should revise derivation and try to remember basic formulas related to derivations..Like Ac generator,Transformer,Mirror formula etc..Revise well..Write in your copy..Many times as possible..Bcz u don't have enough time to solve every numerical of ncert..So derivation and related numerical u can do it in two days.All the best..Bcz they are going to give derivatiion and numericals for sure...But if u will master one area u can perform well there at least...