While it is advised that you be present for the inspection, you need to consider that the Home Inspector has a job to do, they have been highly trained and have a routine they need to follow in order to achieve the best results.  Numerous distractions and questions may cause the Inspector to inadvertently miss something.  Think of being at your job, you know what needs to be done, how well can you do your job with numerous interruptions?

A better plan would be to do your own Inspection, write down all of your questions and then at the conclusion of the inspection, ask the Inspector to discuss your findings, chances are that the Home Inspector will know exactly what you saw and will have the answer!!!

What about uncle Joe?  He is a retired electrician.  Can he be there for the inspection too?

The answer is YES!!!!  You hired the inspector, they work for you.  Most Inspectors are generally knowledgeable in all of the systems of a house, few have specialized knowledge in every system, so let uncle Joe do a more thorough electrical inspection for you.  Most inspectors will gladly listen to a person that has detailed knowledge.