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A Connection Between Why does a compass needle point North? Hans Christian Ørsted • One day as Ørsted was experimenting with electric current, he noticed that a compass needle moved next to a current-carrying wire. • Ørsted had discovered a connection between electricity and magnetism: electric current creates magnetic fields! Magnetic Field Caused by the Motion of Charges a. b. When there is no current in the wire, the compasses align with Earth’s magnetic field. When there is a current in the wire, the compasses shift and align around the wire! Magnetic Field Caused by the Motion of Charges a. b. When there is no current in the wire, the compasses align with Earth’s magnetic field. When there is a current in the wire, the compasses shift and align around A magnetic fieldtheiswire! produced by the motion of electric charges (current). Making an “Electromagnet” • If the wire is bent into a loop, the magnetic field lines become bunched up inside the loop. • If the wire is bent into another loop, the concentration of magnetic field lines inside the double loop is twice that of the single loop. • The magnetic field intensity increases as the number of loops is increased. • A current-carrying coil of wire is called an electromagnet. Making an “Electromagnet” Iron filings sprinkled on paper reveal the magnetic field configurations about a. a current-carrying wire Making an “Electromagnet” Iron filings sprinkled on paper reveal the magnetic field configurations about a. a current-carrying wire b. a current-carrying loop Making an “Electromagnet” Iron filings sprinkled on paper reveal the magnetic field configurations about a. a current-carrying wire b. a current-carrying loop c. a coil of loops Where does our electricity come from? Michael Faraday (1791-1867) discovered that a changing magnetic field through a coil produces an electric current! Investigation Task Your task is to plan and conduct an investigation to provide evidence that: o an electric current can produce a magnetic field, and o a changing magnetic field can produce an electric current.