Observation interview

Hi fellow nurses! I have an interview for a PRN observation unit. I was hoping to get some advice on questions that may be asked during the interview? What a day in the life of an obs nurse looks like? What are maybe some good questions to have to ask the interviewer? This is only my third nursing interview first non new grad interview and I just want to be prepared. Thanks in advance.
Also what are some ratios? Any helpful hints would be great! Thanks