In an experiment designed to measure the earth's magnetic field using the hall effect, a copper bar 0.600 cm thick is positioned along an east–west direction. assume n = 8.46 × 1028 electrons/m3 and the plane of the bar is rotated to be perpendicular to the direction of b. if a current of 8.00 a in the conductor results in a hall voltage of 4.65 10-12 v, what is the magnitude of the earth's magnetic field at this location?

Which of the following is part of the explanation or description of electromagnetic waves? (select all that apply) a. electrically charged molecules in a medium transfer their energy to nearby electrically charged molecules. b. a changing electric field causes a changing magnetic field. c. magnetic molecules in a medium transfer their energy to nearby magnetic molecules. d. a changing magnetic field causes a changing electric field.