These effects are derived from two fundamental observations of physics: a steady current creates a steady magnetic field described by Oersted's law, and a time-varying magnetic field induces an electromotive force in nearby conductors, which is described by Faraday's law of induction.
Butter & salt. Preheat the oven to 400 degrees. Husk the corn, wrap each ear in foil, adding 2 teaspoons of butter to each packet. Bake for about 25 minutes or roast the foil-wrapped corn over hot coals turning once during the cooking. Serve with more butter and salt.
1 Brush the ears of corn generously with the garlic butter; reserve remaining butter.  Cook the corn on the preheated grill, rotating occasionally until the corn is hot and tender, 10 to 15 minutes. Brush the corn with the remaining butter as the corn cooks.