Electricity

What is an Electric Current? The steady flow of electric charges, usually in a wire. Why is it useful?

Imagine if the electric devices you use everyday worked the same way as lightning. Your hair dryer would work for just a second. Your flashlight would flash occasionally. Fortunately, electric devices like these use an electric current, not jumping charges. In these devices, electricity flows steadily. Scott Foresman, Chapter 4; Pg. B116

Conductors A material electricity can flow through. Examples: Metal, Aluminum, Water Can you think of other examples?

Insulators A material that electricity can not flow through. Examples: Rubber, Plastic, Glass Can you think of any others?

What is a Circuit? When you flip a light switch on and off, you are closing and opening a circuit. A circuit is the path that electricity follows. For electrons to travel (creating an electric current), the circuit must be closed. When you flip the light switch off, you are opening the circuit and the lights turn off. When you flip the switch on, the circuit it closed and the lights come on. http://scifiles.larc.nasa.gov/text/kids/Problem_Board/problems/electricity/circuits2.html

Parts of a Circuit The parts used in a circuit depends on the type of circuit being used. In a simple circuit you can use a battery, light bulb, and a wire. What are other parts of a circuit?

LETS DO AN EXPERIMENT!!!

These objects represent electrons inside a wire conductor These objects represent electrons inside a wire conductor. A wire conductor is full of electrons. I will play the part of the battery in this circuit, all batteries have a positive end, represented by my left hand, and a negative end, represented by my right hand. I will pass the "electron" to the student on my right. The student receiving my electron should pass the one he or she is holding to the right. The students continue passing on electrons to the person to their right. Because electrons share the same negative charge, they repel one another, which keeps them moving along in the same direction. The flow of electrons through a conductor is called electrical current. http://www.teachersdomain.org/resource/phy03.sci.phys.mfe.lp_electric/

Check out this video! http://www.teachersdomain.org/asset/phy03_vid_zcircuit/

Lets Practice Working with Circuits http://www.andythelwell.com/blobz/guide.html We will use this sight to learn more about circuits and practice working with them!

Two Types of Circuits Series Circuits Parallel Circuits

Series Circuit In a series circuit, electricity has only one path on which to travel. Electricity flows from the battery to each bulb, one at a time, in the order they are wired to the circuit. In this case, because the electricity can only flow in one path, if one of the bulbs blew out, the other bulb would not be able to light up because the flow of electric current would have been interrupted. In the same way, if one bulb was unscrewed, the current flow to both bulbs would be interrupted. Wikispaces.com; Energy; Circuits

Parallel Circuits In a parallel circuit, electricity has more than one path on which to travel. In these circuits electricity can flow in more than one path, meaning if one of the bulbs blew out, the other bulb would still be able to light up because the flow of electricity to the broken bulb would not stop the flow of electricity to the good bulb. In the same way, if one bulb were unscrewed, it would not prevent the other bulb from lighting up. Wikispaces.com; Energy; Circuits

Resistance The flow of electricity depends on how much resistance is in the circuit. In our examples, the bulbs provide resistance. In a series circuit, the resistance in the circuit equals the total resistance of all the bulbs. The more bulbs in the circuit, the dimmer they will light. In a parallel circuit, there are multiple paths through which current can flow, so the resistance of the overall circuit is lower than it would be if only one path was available. The lower resistance means that the current will be higher and the bulbs will burn brighter compared to the same number of bulbs arranged in a series circuit. Wikispaces.com; Energy; Circuits