Is the IIT Kanpur physics department good?

Yes, the IIT Kanpur Physics department is good. The curriculum is based on research so expect the course to be intensive and rigorous. You will be working with complex equations which will be fun. The faculty are helpful and friendly. They will guide you throughout the course. You will get to experiment and learn about the innovation that is happening in your domain. You will also get the opportunity to do internships. As it is a research institute, you will be encouraged to attend a lot of conferences and even write your journals. Try to get your journal published under the guidance of the faculty members. The scope for higher education is great if you pursue Physics from IIT Kanpur.