An electroscope is a device that detects charge on objects that touch it or are brought near it. John rubs a piece of cotton fabric on a plastic rod and then touches the rod to the electroscope. What methods of charging does John use? John charges the rod through induction, then charges the electroscope through friction. John charges the rod through conduction, then charges the electroscope through induction. John charges the rod through friction, then charges the electroscope through induction. John charges the rod through friction, then charges the electroscope through conduction.