What is voltage? Common everyday batteries such as AAA, AA, or 9V supply electrical energy. Voltage describes the amount of energy available to do work. Imagine a car at the top of a hill. The voltage describes the height of the hill. The higher the voltage, the more kinetic energy you will have when you reach the bottom of the hill. The unit of measure for voltage is called Volts (V). A single AA battery supplies 1.5 volts, whereas our electrical outlets supply 110 volts and thus can give each electron moving in the circuit over 73 times as much energy as the AA battery. What is an electromagnet? An electromagnet is a magnet which is made by flowing current in a wire. It is different from a permanent magnet, which always creates a magnetic field. Both types of magnets will attract iron pins. But, electromagnets are magnets only when we flow current through the wire. Figure 5 A permanent bar magnet made out of a material, such as metal, that has been magnetized Figure 6 An electromagnet formed by flowing current; iron filings line up in the direction of the magnetic field With an electromagnet, the north and south poles are determined by the direction of the current flow. If we look along the axis of the wire loop and the current is circling counterclockwise, then we are looking at the north pole of the electromagnet. If the current is circling clockwise, then we are looking at the south pole of the electromagnet. Figure 7 An electromagnet with the relationship between the direction of its current and its magnetic poles Demonstration of an electromagnet Parts needed per team: Magnetic compass (suggested: Coleman Map - Model No. 2000007838) AA Battery 1.5 V (optional: battery clip) Wire (suggested: a 50Ft spool or a 100Ft spool of UL-Recognized Hookup Wire 26-30 AWG such as Radio Shack 278-502) Optional: 3 alligator clips (suggested: Radio Shack 270-346, which is a pack of 8 clips) Project setup (see video #2) The needle position of the compass, which is shown below before building our electromagnet, points to magnetic north. Earth’s
What is voltage? Common everyday batteries such as AAA, AA, or 9V supply electrical energy. Voltage describes the amount of energy available to do work. Imagine a car at the top of a hill. The voltage describes the height of the hill. The higher the voltage, the more kinetic energy you will have when you reach the bottom of the hill. The unit of measure for voltage is called Volts (V). A single AA battery supplies 1.5 volts, whereas our electrical outlets supply 110 volts and thus can give each electron moving in the circuit over 73 times as much energy as the AA battery. What is an electromagnet? An electromagnet is a magnet which is made by flowing current in a wire. It is different from a permanent magnet, which always creates a magnetic field. Both types of magnets will attract iron pins. But, electromagnets are magnets only when we flow current through the wire. Figure 5 A permanent bar magnet made out of a material, such as metal, that has been magnetized Figure 6 An electromagnet formed by flowing current; iron filings line up in the direction of the magnetic field With an electromagnet, the north and south poles are determined by the direction of the current flow. If we look along the axis of the wire loop and the current is circling counterclockwise, then we are looking at the north pole of the electromagnet. If the current is circling clockwise, then we are looking at the south pole of the electromagnet. Figure 7 An electromagnet with the relationship between the direction of its current and its magnetic poles Demonstration of an electromagnet Parts needed per team: Magnetic compass (suggested: Coleman Map - Model No. 2000007838) AA Battery 1.5 V (optional: battery clip) Wire (suggested: a 50Ft spool or a 100Ft spool of UL-Recognized Hookup Wire 26-30 AWG such as Radio Shack 278-502) Optional: 3 alligator clips (suggested: Radio Shack 270-346, which is a pack of 8 clips) Project setup (see video #2) The needle position of the compass, which is shown below before building our electromagnet, points to Earth’s magnetic north.
HarnessingEnergy.docx