Hii Mithila!
The solutions foe most of the questions in S.L Arora physics book for class 11th and 12th are provided in the book itself. There are solved examples, ncert exercise solutions and solutions of problems to be solved by you are also given. If you are talking bout the questions at the end of the book, that you need to solve your self after going through the chapter. If not, you may take help of your teacher.
Hope you understand.
Good luck!