MARCH Right Now: Get Electricity notes Agenda: 1- Notes: Electricity 2- Circuit Drawing Objectives: I CAN…Describe how simple circuits are associated with the transfer of electrical energy. Explain how simple electrical circuits can be used to determine which materials conduct electricity.

electricity electricity

Think about it… Have you ever reached out to open a door and received a shock from the doorknob? Why did that happen? The shock came from STATIC ELECTRICITY. To understand this, you need to learn about atoms and charges.

Atoms and Charges All matter is made up of very small particles called atoms. Atoms are made of even smaller particles called protons, neutrons, and electrons. How do these particles differ? particles differ?

Electric Charges Protons and electrons are charged particles, and neutrons are not. Charge is a physical property. An object can have a positive charge, a positive charge, a negative charge, or negative charge, or no charge. no charge.

The Law of Electric Charges Charged objects exert a force --a push or pull-- on other charged objects Like charges repel, or push away Opposite charges attract Protons are positively charged Electrons are negatively charged

Show what you know! The figure shows a negatively charged plastic comb picking up pieces of uncharged tissue paper. Determine the best explanation for why this might happen. A. Electrons are transferred from the comb to the tissue paper due to friction. B. The comb induces a positive charge on the surface of the tissue paper. C. Electrons move from the comb to the tissue paper by direct contact. D. The tissue paper becomes negatively charged by conduction.

Conductors and Insulators Have you ever noticed that electrical cords are made from metal and plastic? Different materials are used because electric charges move through some materials more easily than others. Most materials are either conductors or insulators based on how easily charges move in them. The answer is B

Conductors and Insulators An electrical conductor is a material in which charges can move easily. Most metals are good conductors because some of the electrons are free to move. An electrical insulator is a material in which charges cannot move easily. They do not conduct charges very well because their electrons cannot flow freely. Plastic, glass, rubber and wood are good insulators.

The insulating material in a lamp cord stops the charges from leaving the wire and protects you from electric shock.

Show what you know! List three electrical conductors: List three electrical insulators: Why do you think static electricity occurs? Static electricity is the electric charge at rest on an object. Something static is not moving. The charges do not move away from the object they’re in, so the object keeps its charge. Charges that build up eventually leave – an electric discharge – such as when you touch a metal doorknob or even lightning! ( p.421)

Think about it… How does a light switch turn lights on and off?

Electrical Energy You might not realize that when you watch TV, use a computer, or even turn on a lightbulb, you depend on moving charges for the electrical energy that you need. Electrical energy is the energy of electric charges. In most of the things that use electrical energy, the electric charges flow through wires.

Electric Circuits Just like a roller coaster, an electric circuit always forms a loop—it begins and ends in the same place. Because a circuit forms a loop, a circuit is a closed path. So, an electric circuit is a complete, closed path through which electric charges flow. All circuits need three basic parts: an energy source, wires, and a load. Loads, such as a light bulb or a radio, are connected to the energy source by wires. Loads change electrical energy into other forms of energy. These other forms might include thermal energy, sound energy, light energy, or mechanical energy.

Simple Circuit

A Switch To Control a Circuit   Sometimes, a circuit also contains a switch. A switch is used to open and close a circuit.   Usually, a switch is made of two pieces of conducting material, one of which can be moved.   For charges to flow through a circuit, the switch must be closed, or "on."   If a switch is open, or "off," the loop of the circuit is broken. Charges cannot flow through a broken circuit. Light switches, power buttons on radios, and even the keys on calculators and computers open and close circuits.

Switches

Show what you know! Draw a simple electric circuit. Include: Battery (energy source) Battery (energy source) Wires Wires Load (choose light bulb or sound buzzer) Load (choose light bulb or sound buzzer) CHALLENGE: Draw two electric circuits with battery-wires-load with one switch in the “on” position and the other switch in the “off” position.

Series Circuits A series circuit is a circuit in which all parts are connected in a single loop. There is only one pathway for moving charges, so any break in the circuit causes charges to stop flowing. All of the loads in a series circuit share the same current. Because the current in each bulb is the same, the lights glow with the same brightness. (Adding more bulbs weakens current, dims lights) Good examples are a string of holiday lights and burglar alarm systems.

Parallel Circuits A parallel circuit is a circuit in which loads are connected side by side. Charges in a parallel circuit have more than one path on which they can travel. Unlike the loads in a series circuit, the loads in a parallel circuit do not have the same current. Instead, each load in a parallel circuit uses the same voltage. Each bulb glows at full brightness no matter how many bulbs. If one light goes out, the others stay lit because there is still a path for the electrons to follow. Example: Electrical outlets in your home

Show what you know! Sarah can have all five appliances in her kitchen on at the same time or she can have each appliance on one at a time. How are the appliances in Sarah’s kitchen wired? A)in a voltage circuit B)in a direct current circuit C)in a parallel circuit D)in a series circuit

Show what you know! Draw a Series Circuit using 3 light bulbs. Draw a Parallel Circuit using 3 light bulbs.