I've been to seven or eight interviews and after awhile they are all the same. Your first one will be the most intimidating, but after that you'll feel like a professional interviewer.
Usually, the activities begin at 9:00 in the morning and conclude between 12:00 and 1:00. You and other applicants (professionally dressed) all sit in large conference room making small talk, sipping coffee and enjoying simple carbs provided by the program.
The interview usually involves just one faculty member. You could however interview a faculty member and a current student, or you could interview one faculty member, and then another (not simultaneously).
At some point, a current student will you give a tour of the facilities, and will answer any questions you have. At most programs, there is a separate session for questions. Believe me, you will have enough time to ask questions, and might think the students are too solicitous. They're just trying to be good ambassadors.
Questions to expect include:
"Why do you want to be a PT?"
"How do you deal with difficult people?"
"How do you handle conflict?"
"What attracted you to our program?
"How do you work in groups?"
"How do you deal with stress?"
"What are some positive qualities that you bring to the profession?"
"If you do not get accepted anywhere, what will you do?" (kind of rude in my opinion)
"Do you think you can adjust to (insert city here)?"
You ask them:
"What do you do here?"
"What makes you proud of this program?"
"Are there any changes you would make to this program?"
"What do you expect of your students? What makes a good student?"
"Do you do any advocacy work?"
If I think of more, I'll edit this post.
Kevin