No live operation will be entrusted to a minor trainee. he won't be left without supervision if he's in premises where there's risk of entering in contact with bare live parts (article D. 4153-24 of the labor code). An exception may be made in the case of very low voltage (<50V in a dry environment). If he holds an electrical authorization, he will be able to carry out operations on electrical installations or electrical or non-electrical operations in the vicinity of these installations (article R. 4153-50 of the Labor Code) They can be empowered B0, H0 for non-electrical work and at maximum  B1, H1, B1V for electrical work (interministerial circular no. 11 of October 23, 2013