Robin has an iron rod around which she wraps copper wire. She places the device on a table near a compass. What will happen to the compass if she sends current through the copper wire?

What is the thinnest soap film (excluding the case of zero thickness) that appears black when illuminated with light with a wavelength of 480 ? the index of refraction of the film is 1.34, and there is air on both sides of the film. express your answer in nanometers. hint 1. how to approach th