1-3 Electric Current and Magnetic Fields

Electric Current Electric Charge - all protons and electrons have an electric charge. The flow of electric charges produce an electric current. Ampere (A or amps) - unit used to measure the amount of charge that flows in a given time Electric Charge - all protons and electrons have an electric charge. The flow of electric charges produce an electric current. Ampere (A or amps) - unit used to measure the amount of charge that flows in a given time

An electric current produces a magnetic field (p. 31) The field produced effects compasses just as a magnet does An electric current produces a magnetic field (p. 31) The field produced effects compasses just as a magnet does

Moving Charge and Magnetism All magnetism is caused by the movement of charges. The movement of charges is also responsible for electric current. All magnetism is caused by the movement of charges. The movement of charges is also responsible for electric current.

Electric Circuits Electric currents need a circuit in order to flow. A circuit is a closed path for the current to travel through. All electrical devices contain circuits Electric currents need a circuit in order to flow. A circuit is a closed path for the current to travel through. All electrical devices contain circuits

All circuits have the same basic features A source of electrical energy (power source) Ex. Battery A device that is run by electrical energy Ex. Light Bulb Conducting wires and a switch See p. 31 All circuits have the same basic features A source of electrical energy (power source) Ex. Battery A device that is run by electrical energy Ex. Light Bulb Conducting wires and a switch See p. 31

Conductors and Insulators Electric current does not flow through every material Conductors allow electricity to flow freely Ex. Copper, silver, iron, aluminum Conductors have loosely bound electrons in their atoms, that allows the electrons to to flow through the material-->forms a current Electric current does not flow through every material Conductors allow electricity to flow freely Ex. Copper, silver, iron, aluminum Conductors have loosely bound electrons in their atoms, that allows the electrons to to flow through the material-->forms a current

Insulators do not allow electricity to flow freely Ex. Rubber, wood, glass, plastic Electrons are bound tightly to their atoms and do not flow easily. Conducting copper wire is covered by a plastic coating so that it can be handled safely while currents flow through it. Insulators do not allow electricity to flow freely Ex. Rubber, wood, glass, plastic Electrons are bound tightly to their atoms and do not flow easily. Conducting copper wire is covered by a plastic coating so that it can be handled safely while currents flow through it.

Electrical Resistance A resistor uses electrical energy as it interferes with the flow of charge Many times the energy is transferred into another form Ex. Light bulb --> electrical energy to light and heat energy Best example: Walking through a crowd. Stand up, let’s try it. A resistor uses electrical energy as it interferes with the flow of charge Many times the energy is transferred into another form Ex. Light bulb --> electrical energy to light and heat energy Best example: Walking through a crowd. Stand up, let’s try it.

Superconductors A material that has NO electrical resistance This would allow an electrical current to flow with out losing any energy Computers could be the size of a watch and be just as effective and powerful as a typical desktop computer. A material that has NO electrical resistance This would allow an electrical current to flow with out losing any energy Computers could be the size of a watch and be just as effective and powerful as a typical desktop computer.