for electrical resistance welding the surface of metal must be All Questions › Category: Basic Electrical › for electrical resistance welding the surface of metal must be 0 Vote Up Vote Down Rajasri Mundrathi Staff asked 3 years ago Options: a) rough.b) clean.c) moistenedd) Coloured 1 Answers 0 Vote Up Vote Down Rajasri Mundrathi Staff answered 3 years ago The correct answer is Clean