I am installing a new patio and want to run some lighting before the pad goes in. I have not decided whether to run 120VAC out to the pad edge...and connect a low voltage transformer near the light location OR run the low voltage wire from the house all the way to the fixture. My questions are

1. What is the code for the depth I need to bury the conduit if I run 120VAC?

2. Is there any similar code for the low voltage line (assuming the transformer has over current protection)?

3. Do I need to use conduit with the low voltage line?

4. is 120VAC or low voltage the preferred way to get power from the house near the location it is needed?

Thanks for any help.