Unit 8 Electricity and Magnetism
Page 9: Essential Question 1 What causes charged objects to push and pull on each other?
Page 8 - How do objects get an electrical charge? O Review: Parts of the Atom O Electron: negative charge; outside of the nucleus O Proton:positive charge, in the nucleus O Neutron: no charge, in the nucleus.
Page 8 - How do objects get an electrical charge? O Charged: An unequal number of protons and electrons O Neutral: An equal number of protons and electrons
Page 10 - How do objects get an electrical charge? O Three Ways for objects to become charged. 1. Friction 2. Conduction 3. Induction
Page 10 - How do objects get an electrical charge? O Charging by Friction O When electrons are rubbed off of one object onto another.
Page How do objects get an electrical charge? O Start with 2 Neutral objects and end with 2 opposite charged objects.
Page 10 - How do objects get an electrical charge? O Charging by Conduction O Electrons are transferred from one object to another by contact.
Page 10 - How do objects get an electrical charge? O Start with 1 Neutral and 1 Charged and end with 2 like charges.
Page 10 - How do objects get an electrical charge? O Charging by Induction O When the charges in an uncharged object are rearranged without direct contact.
Page 10 - How do objects get an electrical charge? O When the charged object leaves, the induced charge goes away.
Page 10 - How do objects get an electrical charge O The Law of Conservation of Charge O Electrons cannot be created or destroyed, they simply move from one object to another.
Page 10- How do objects get an electrical charge? O Electroscope: Tool used to detect electrical charge.
Page 10 - How do objects get an electrical charge?
O Electrical Force: When Electrons and Protons push or pull on each other.
Page 127- How do objects get an electrical charge? O The Law of Electrical Charges O Opposites charges attract and like charges repel.
Page 10- How do objects get an electrical charge?
Page 12- How do objects get an electrical charge? O Static Electricity: When charges build up on an object.
Page 12- How do objects get an electrical charge? O Electrical Discharge: loss of static electricity as charges move off the object.
Page 12- How do objects get an electrical charge?
Page 14 – Electrical Materials How do we try to control electrical energy?
Page 14– How do we try to control Electrical Energy? O We try to control the movement of electrons by using conductors, insulators and semiconductors.
Page 14– How do we try to control Electrical Energy? O Electrical Conductor: Materials that electrons move through easily. O Examples: ALL METALS.
Page 14– How do we try to control Electrical Energy?? O Electrical Insulators: Materials that electrons have a difficult time moving through. O Examples: ALL NONMETALS
Page 14– How do we try to control Electrical Energy? O Electrical Semiconductors: Allows electrons to flow only one direction through the material. O Examples: METALLOIDS ( Silicon)
Page 14– How do we try to control Electrical Energy?
Page 16 – Parts of Electrical Circuits O Current: the rate at which charge passes through a conductor. O More current means more charge.
Page 16: Parts of Electrical circuits O Alternating Current (AC) O Current that travels back and forth through a wire. O Current in our Homes.
Page 16 O Direct Current O Current that only flows one way through a wire O Current that comes from a battery or solar panel.
Page 16 O Voltage: The amount of energy released as a charge moves from one place to another. O How hard the electrons are pushed through a conductor.
Page 16 O Resistance: the opposition to the flow of electrical charge. O Insulators have a high resistance and conductors have a low resistance.
Page 14 O The size of the conductor affects the resistance. 1. A wider wire (bigger diameter) has less resistance. 2. A shorter wire has less resistance.
Page 14 O Temperature affects resistance O Higher temperatures make more resistance.
Page 16 – OHM’S LAW Ohm’s Law SymbolNameUnit VVoltageVolts (V) ICurrentAmperes (A) RResistance Ohms ( )
Page 16 – Ohm’s Law Example Problems O How much current flows from an electrical eel if it can generate a voltage of 600 V through water with a resistance of 100 Ω ?
Page 14 – Ohm’s Law Example Problems O What is the resistance of the human skin if a 9.0 V battery causes 0.02 amps of current to flow through the skin?
Page 20 Electric Circuit Basics O How do electrical circuits work?
Page 20 – How do electrical circuits work? O Water Analogy
Page 20 – How do electrical circuits work? O Parts of a circuit O Power Supply O Wire/Conductor O Load/Resistance
Page 20 – How do electrical circuits work? O Open and Closed Circuit O A circuit must have a complete path (closed circuit) for electrons to flow.
Page 20 – How do electrical circuits work? O Other Electrical Devices O Switch: Opens and Closes a circuit O Solar Cells: Creates DC current when light hits it.
Page 20 – How do electrical circuits work? O Series Circuit: All parts are connect in a single loop.
Page 20 – How do electrical circuits work? O Parallel Circuit: Parts are connected in separate branches of the circuit.
Page 22 – How do electrical circuits work? O Diode: A semiconductor that only allows current to flow one way through the circuit. O LED (light emitting diode): Gives off visible or Infrared light when electricity flows through it.
Page 24- What is a Magnet? What are properties of magnets?
Page 24– What are properties of Magnets? O What to find in the reading O What is a magnetic field? O What are the ends of a magnet called and how do they interact with each other? O Where is a magnetic field the strongest? O How does a piece of iron become a magnet? O What happens when a magnet breaks? O How is an electromagnet made? O How do we use magnets to make electricity?
Page 24 – What are properties of magnets? O Magnet: any material that attracts iron or materials containing iron.
Page 24 – What are properties of magnets? O Magnets have poles. O North Pole and South Pole
Page 24 – What are properties of magnets? O Opposite poles attract and like poles repel.
Page 24– What are properties of magnets? O Magnets create a Magnetic Fields that are strongest at the poles.
Page 24 – What are properties of magnets? O Breaking a Magnet in half creates two new magnet.
Page 26 - Essential Question 5 How to make temproray magnets?
Page 26 – How do we make magnets? O A wire carrying a current makes a magnetic field around the wire.
Page 26 – How do we make magnets? O Solenoid: A coil of wire that produces a concentrated magnetic field.
Page 26 – How do we make magnets? O An iron core becomes an electromagnet when it is placed inside a solenoid.
Page 26 – How do we make magnets? O Electromagnet: a magnet made by wrapping a wire around an iron core and hooking the wire up to a power source.
Page 26 – How do we make magnets? O Electromagnets are temporary magnet that stops when the current stops.
Page 26 – How do we make magnets? O How to make a stronger Electromagnet 1. More turns (loops) of wire 2. More current 3. More Iron Core
Page 28? O Electrical Generator: Converts mechanical energy to electrical energy.
Page 24 O Wire spins inside a magnetic field!
Page 24 O What is the energy conversion for a coal burning power plant?
Page 30 O Electrical Motor: Converts electrical energy to mechanical energy. O Opposite of a generator, it is a generator that is reversed.
Page 30 Current in the wire causes the wire to spin in the magnetic field.
Page 30 O Where can you find examples of electric motors?