What is a conductor?
Conduction is a general term used whenever you are talking about moving something from one place to another. One familiar example is a conductor on a train. A train conductor helps move people from place to place. In this video we’re looking at another type of conduction – heat energy conduction. Barkley is experimenting with the conduction of heat energy from a hotter to a cooler item. Heat energy always travels from a hotter to a cooler material. In a solid material, like Barkley’s experimental oven mitts, heat energy moves from the mitts to Barkley’s hands since those items are touching each other. Not all solids are good conductors of heat. Barkley’s mitts were made of metal. As you could see from the video, metal is a very good conductor of heat. When Ted used Barkley’s mitts, heat energy was transferred to the surface of the mitts by touching the metal rack in the oven. The metal gloves passed the heat energy to Ted’s hands — not a good idea. The movement of heat energy can be u
National Science Education Standards: Content Standard A: Science As Inquiry Content Standard D: Physical Science – Light, heat, electricity and magnetism These activities help students experience and understand how a conductor carries heat energy. (BACKGROUND INFORMATION) What do we already know about conductors? • Heat energy conduction occurs when heat energy moves from a hotter to a cooler item. • Heat energy always travels from a hotter to a cooler material. • Not all solids are good conductors of heat. • Poor heat conductors are called insulators. Activity One – Act it Out! a bag of similar items such as paper clips, marbles, or any small item that fits inside the bag • Before the simulation: Fill a bag with similar items such as paper clips, marbles or any small item that fits inside the bag. Include enough items for about 1/2 of the students involved in the simulation. • Explain that you will be directing the students to “act” out the movement of heat energy by playing a modifi
• Units of Conductor Size • National Electrical Code • Conductor Materials • Insulation Materials • Correction Factors • Number of Conductors • Conductor Fill • Length of Conductors • Voltage Drop Calculations • Additional Conductor Protection • Understanding Code Tables • Using the NEC Tables: An Example • Summary
of light is a substance that permits the flow of light. Interestingly, most conductors of light are not good conductors of electricity – they are insulators – but may or may not also be good thermal insulators. For instance diamond is a good conductor of light, is a conductor of heat but is still a good electrical insulator.
