Do you want possible answers as well?
Plus, make sure he is prepared with a list of good questions for them at the end as that can be a deciding factor between 2 good candidates (search on my name for some as I put some suggestions on a thread in January)
How do you galvanise your team into action? (Lead by example, not afraid to muck in, have a full understanding of my role plus theirs to appear credible, be enthusiastic, explain required outcome for what they are doing, ensure praise given when due as they will remember that)
How do you motivate your staff? Ensure the rate they are paid reflects the role they are in, carry out regular performance reviews, ensure they have set goals and realistic targets, have regular catch up meetings to assess workloads and see if they need help with anything, hold team meetings to keep them updated, delegate work to give them extra responsibility and exposure to new things, be honest with them, make sure you know your stuff so they respect you, give them development opportunities.
Competenty questions relating to honesty/integrity, leadership ability, communication, planning and executing work, prioritising, managing change, budgeting, dealing/diffusing with conflict/difficult situations, pressure, teamwork etc (think of examples for each so you are prepared)
Staff issies such as dealing with disciplinary or performance or grievance (depends on company policy)
What are your main strengths
What are your main weaknesses (or areas that require improvement) - have examples prepared