I'm not sure if I'm representative, but in my phone interviews, I was always asked:
- Where do you want to be in 5 years? 10 years? (AKA - academia, job placement, etc.)
- Tell me about x research experience from your CV (I got lots of questions about my undergrad thesis)
- Do you have research experience with X or Y?
- Are you open to researching (insert completely different topic than is listed on the POI's CV)?
- Do you have any questions for me?
I also asked all sorts of questions of the POI about the program, graduates, department, etc.
You'll do fine!