Dear student,

I would not recommend you to study the theory of modern physics from H.C Verma. The theory given in the book is not sufficient and does not explains the concept well. However the problems are really good. I would advice you to study this topic from Resnick Halliday, it is a great book for theory for physics. You concepts will build up strongly and you will understand the topic really well. After reading from this book you can go to hc verma and solve it's problems.