Agenda for 6/1/16 State Assessment Quiz Unit 8 (LAST UNIT) – Electricity and Magnetism Electric Charge Notes HW – Static Electricity Worksheet

Unit 8 Electricity – The Shocking Truth About Our Current Unit! Charges, Currents, and Circuits

Electric Charge Protons have positive electric charge; electrons have negative electric charge. Atoms become charged by gaining or losing electrons

Law of Charges Like charges repel and Unlike charges attract. Repel: charges are the same Attract: charges are opposite

Law of Charges If an object has more electrons than protons, it has an overall negative charge. If an object has more protons than electrons, it has an overall positive charge.

Electrons move more easily through conductors, like metals. Electrons do not move easily through insulators, such as plastic, wood, rubber, and glass.

Transferring electric charge by contact: The process of transferring charge by touching or rubbing Example: static electricity from your feet rubbing the carpet Transferring electric charge without contact: The rearrangement of electrons on a neutral object caused by a nearby charged object.

Static electricity - is stationary or collects on the surface of an object Current electricity - is flowing very rapidly through a conductor. The flow of electricity in current electricity has electrical pressure or voltage. Electric charges flow from an area of high voltage to an area of low voltage.

Static Electricity The electric charge can be: A. Positive B. Negative _

Examples of Static Electricity A. Combing your hair with a plastic comb - electrons move from comb to hair. B. Scuffing carpets with feet.

Examples of Static Electricity C. Touching Doorknob D. Balloon on Wall

Examples of Static Electricity Kick feet under covers of bed.

Examples of Static Electricity Lightning Van de Graff generator - deposits electrons on the ball. When a person places their hand on the ball and the machine is turned on, electrons are transferred to and collected on the person touching the silver ball.

Agenda for 6/6/16 Electric Current Notes Ohm’s Law Triangle worksheet HW - None

Electric Current Current - The flow of charges (electricity) through a wire or conductor. Current is measured in amperes (A). Voltage - rate at which energy is drawn from a source that produces electricity. Charges flow from high voltage to low voltage. A voltage difference is the push that causes charges to move. Measured in volts (V).

Resistance - a force that tends to oppose motion. Measured in ohms (Ω).

Comparing to water flow Current - amount of water flow through pipes leading to a faucet. Voltage - the force or "pressure" causing the water to flow. Resistance - The larger the pipe and the faucet (less resistance), the more water that comes out! The smaller the pipe and faucet, (more resistance), the less water that comes out!

The relationship between voltage difference, current, and resistance in a circuit is known as Ohm’s Law. Ohm’s Law states that the current in a circuit equals the voltage divided by the resistance.

Ohm’s Law Formulas: I = V R R = V I V = IR

Agenda for 6/7/16 Circuit Notes Parallel and Series Circuit Worksheet HW – Circuit Review Worksheet

Circuits

Circuits All electrical devices use the flow of electrical charges. Examples of electrical energy: 1) Generators (from power plants) 2) Batteries – Wet Cell and Dry Cell 3) Electromagnetic - Moving a magnet through a coil of wire causes the electrons to flow through the wire. 4) Solar Cells

Batteries are composed of a chemical substance which can generate voltage which can be used in a circuit. The zinc container of the dry cell contains a moist chemical paste surrounding a carbon rod suspended in the middle.

Wet cell batteries are most commonly associated with automobile batteries. A wet cell contains two connected plates made of different metals or metal compounds in a conducting solution.

Circuit - a complete path (closed) for electricity to follow. Electricity flows from negative to positive.

Circuits A circuit contains loads – which are devices that use electricity. Examples: TV Radio Appliances

Circuits Some circuits that carry a large amount of electricity are grounded with a third prong.

Types of Circuits: 1) Series Circuit - the current has only one loop to flow through “One Path” circuit. The parts of a series circuit are wired one after another, so the amount of current is the same through every part. Open Circuit—if any part of a series circuit is disconnected, no current flows through the circuit Brighter light Example: strings of holiday lights.

2) Parallel Circuit – contains two or more branches for current to move through Each load has its own path back to the source of electricity. “Multiple Path” circuit. Homes and apartments are wired in a parallel circuit. Individual parts can be turned off without affecting the entire circuit. If a lamp goes out, other appliances in your home are not affected.

Drawing Circuit Diagrams: Determine if it is a series or parallel circuit Use symbols of a battery, wire, switch, resistors/light bulbs

Common Circuit Symbols

What kind of circuit?

Agenda for 6/8/16 Go over homework Magnetism notes HW – None

Magnetism - is the force of attraction or repulsion of a magnetic material due to the arrangement of its atoms, particularly its electrons.

Magnets have been known for centuries. The Chinese and Greeks knew about the “magical” properties of magnets. The ancient Greeks used a stone substance called “magnetite.” They noticed that chunks of this mineral could attract pieces of iron.

The ends of a magnet are where the magnetic effect is the strongest The ends of a magnet are where the magnetic effect is the strongest. These are called poles. Each magnet has 2 poles 1 north and1 south.

Like repels like Opposites attract!

Poles of a magnet always come in pairs!

If you cut a magnet in half, you get 2 magnets!

The region where the magnetic forces act is called the magnetic field

Agenda for 6/10/16 Finish notes Work on Electricity and Magnetism worksheet HW – whatever you don’t finish in class

Atoms themselves have magnetic properties due to the spin of the atom’s electrons. Groups of atoms join so that their magnetic fields are all going in the same direction These areas of atoms are called domains

When an unmagnetized substance is placed in a magnetic field, the substance can become magnetized. This happens when the spinning electrons line up in the same direction.

An unmagnetized substance looks like this…

While a magnetized substance looks like this…

How to break a magnet: 1. Drop it Heat it (this causes the domain to become random again)

The Earth is a magnet: It exerts magnetic forces and is surrounded by a magnetic field that is strongest near the North and South magnetic poles Magnetic South Pole Geographic North Pole Magnetic North Pole Geographic South Pole

We use the Earth’s magnetic field to find direction. The needle of a compass always points toward the magnetic south pole. We call this direction “North” (remember, opposites attract)

Agenda for 6/14/16 Go over Study Guide Whiteboard Review Electricity and Magnetism Test tomorrow HW - Study

Whiteboard review Give 3 examples of static electricity. Rubbing balloons Scuffing shoes Lightning Van De Graff generator Touching metal door knob

What are the charges for a proton and an electron? Proton – positive Electron - negative

If an object has more protons than electrons, the overall charge of the object will be positive

If a neutral object gains electrons, the overall charge the object will be negative

Electrons move more easily through ______________ and do not move easily through _________________. Conductors, insulators

Electrical charges flow from an area of __________ voltage to an area of _____ voltage High to low

The flow of charges through a wire or conductor is called what? Current

What are the units for current? amperes

What is the rate at which energy is drawn from a source that produces electricity? What are the units for it? Voltage - volts

What kind of circuit? Series

What kind of circuit? Parallel

How many loads does this circuit have? What kind of circuit is it? 3 Series

What kind of circuit is A? B? A – Series B - Parallel A. B.

What poles in a magnet repel each other? North and North South and South

What is one way to break a magnet? Drop it Heat it

VOTE Chemistry vs Physics?