Question

how can we get more marks in physics?

Answer 1

By doing more studies

Answer 2

1. Do each and every derivation thoroughly. Don't just mug them up, understand them. Practice all the diagrams involved so that you're prepared to simply print the answer on the sheet. They are very scoring. So make sure you know every derivation. 
2. Make a list of all.the formulas that you come across and revise them everyday. It'll do wonders for you.
3. Don't start with ncert questions. They are relatively tough and don't come very often. Instead buy arihant and do all the previous year questions honestly. Understand the concepts behind each and every answer. And don't just do them once. Do them at least 5-7 times. It'll make you every confident and help you answer majority of questions.
4. Now start with the sample paper questions. Collect sample papers of the last 10 years and do all questions. Give special emphasis on the samples of last 3 year. 
4. Now if you still have some energy left then start with ncert. 1st do the solved examples only. They are more likely to come for the exam. Then the back questions. And NOT ALL of them. Only a few selected ones which are normal.