A metal detector uses a coil to find pieces of metal that are buried or otherwise obscured. When a piece of metal is moved near a metal detector’s coil, an emf is induced in the coil. All else being equal, the induced emf is largest for metals that behave as permanent magnets (Chapter 20) such as iron and nickel. Assume a coil of diameter 10 cm with 500 turns is scanned over a large piece of iron that is just below the soil’s surface. Estimate the magnitude of the emf induced in the coil. Assume the field near the iron is B = 0.30 T.