1 / 19

Electricity and Magnetism Circuits Electromagnets

Electricity and Magnetism Circuits Electromagnets. Chapter 17 and 18. How can you produce electricity?... right now!. The Law of Electric Charge. Like charges repel – push away Opposites attract. Electric Field. Charge It – How do we create charge?.

helia
Télécharger la présentation

Electricity and Magnetism Circuits Electromagnets

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Electricity and MagnetismCircuitsElectromagnets Chapter 17 and 18

  2. How can you produce electricity?...right now!

  3. The Law of Electric Charge Like charges repel – push away Opposites attract

  4. Electric Field Charge It – How do we create charge? Friction – electrons are “wiped” from one object to another Conduction – electrons move through direct contact (a shock!) Induction – when charges are rearranged without direct contact • A region around a charged object in which an electric force is exerted on another charged object.

  5. What is an electric circuit? • A complete loop (begins and ends at the same place) through which electric charges flow.

  6. Voltage • The unit of measure for potential difference is the Volt (V) • Think 9 volt battery • The device that provides the potential difference is considered the voltage source;

  7. Current • The current is the rate at which a charge passes a given point • The unit for current is the ampere or Amp (symbol - A) • An amp is the amount of current that flows past a point in one second

  8. How does the flow begin? • Electrons in a circuit have potential energy • The potential energy of each charge is called electrical potential • In a battery, the electrical potential of one terminal is higher than the other terminal • The difference in this potential energy is called potential difference • This potential difference causes the loose electrons to be pulled away from their atoms and flow through the material

  9. The Essential Parts of a Circuit • An energy source – battery etc. • Wires – to carry the electric charge • Load – light bulb, radio etc.

  10. Switches • Some circuits in include a switch to open and close the circuit (turn it on and off) • Open – off (the loop is broken) • Closed – on (the loop is closed or complete)

  11. Types of Circuits • The parts of a circuit can be connected in different ways. The two main types are: • Series • Parallel

  12. Series Circuits • All parts are connected in a single loop • All loads in a series circuit share the same current

  13. Series Circuit • Will all bulbs burn with the same brightness? • Yes, all receiving the same electric current. • What will happen if I add a bulb? • They will all dim b/c they will receive less electric current. • What happens if one bulb burns out? • They will all go out, the loop is no longer complete.

  14. Parallel Circuit • A circuit in which loads are connected side by side • Current in a parallel circuit has more than one path • Each load receives the full amount of energy the energy source can provide (voltage) and they will use as much current as they need • Ex. 45 vs. 60 Watt light bulb

  15. Parallel Circuits • Will all bulbs burn with the same brightness? • No, it depends on their wattage. • What will happen if I add a bulb? • They will continue to burn with the same brightness. • What happens if one bulb burns out? • The remaining bulbs will stay lit.

  16. Questions to Consider: • Which circuit would be more useful in lighting a home or building? • Parallel, you want to be able to have the lights on in one room and off in another. • Which circuit is used in Christmas tree lights? • It depends, they used to be made in series, if one burned out all went out. Nowadays many are made in parallel so the remaining bulbs will continue to burn. • Why are series circuits useful? • Burglar alarms • What drawbacks are there in using parallel circuits?

  17. How does a compass work? • It is a magnet that works, moving from its north/south orientation only when it is no longer aligned with the earth’s poles • A man, Hans Oersted, found that when a compass is held near a wire that is passing electric current the compass would move even if it was still aligned with the poles.

  18. What is a solenoid? • Electricity and magnetism are closely related. This was first seen when a solenoid was developed. • A solenoid is simply a coil of wire that when current is flowing through it will generate a magnetic field.

  19. Electromagnet: • A stronger version of the solenoid! • It creates atemporary magnet when a current-carrying wire coil surrounds a magnetic metal core. • Useful because they can be turned off • Adding and removing coils can increase or decrease strength

More Related