07.+Electric+Current+and+Circuits


 * vocab: Electric current and circuits**
 * 1) electric current- a flow of chargerd particles
 * 2) coventional currrent- a flow of positive charges that move from higher potential to lower potential
 * 3) battery- a device made up of several galvanic cells connected together that converts chemical energy to electric energy
 * 4) electric circuit- a closed loop or pathway that allows electric charges to flow
 * 5) ampere- a flow of electric charge, or electric current, equal to one colomb per second (1 c/s)
 * 6) resistance- a property that determines how much current will flow; is equal to voltage divided by current
 * 7) resistor- a device with a specific resistance may be made long,thin wireless, graphite, or semiconducters and often is used to control the current in curcuits or parts of ciruits.
 * 8) parallel connection- a type of connection in which the ciruit compound and the voltmeter are aligned parallel to one another in the ciruit
 * 9) ﻿﻿﻿series connection- a type of connection in which there is only a single current path
 * 10) superconductor- is a material with zero resistance
 * 11) kilowatt-hour- is equal to 1000 watts delivered continually for 1hr.

R=V/I
 * Electiric Current Notes:**
 * __Ohm's Law__: Ohm's law states that current is directly proportional directly proportion potiental diffrence. suppose two conductors have a potiental diffrence between them. They are connected with a copper rod between them creates almost no current**.


 * __key concept:__ The key concept is to explain energy transfer in circuits and diagram simple electric circuits. You will also be able to distringuish parallel connection from series connections.**

__**How key concepts realate to other physics concepts**__ The topic Current Electricity and Series and Parallel Circuits relates to many other various physical quantities in different ways. If you talk about Current electricity you have to talk about electrons, protons and neutrons. To understand these things you must first understand the basic qualities of each part of the subject to fully understand your topic. The key concepts in Chapter 22 are very important, for that to be true they must all be important from chapter 1 through 22, 23,....ect. __The Relationship To Key Concept__ The relationship between the key concept and real life is that, the reality is that we use electricity every day. We walk, live, eat, and sleep around electric current wheather you are in your car and you go under the stop light, or turn on the light to use the bathroom at your house or anything. We use electricity almost every single day of life, we wouldnt be able to take a hot shower with out electric currents running through your hot water heater. With the information provided on this webpage we can better understand electricity and apply it to our every day life situations.
 * __Rates of charge how and energy transfer__: Power, which is defined in watts, w, measures the rate at which energy is transferred. If a generator transfers is of kinetic energy to electric energy each second it is transferring energy at the rate of 1 j/s or 1 w.**
 * currrent is the rate of charge movment**


 * A current exists whenever where is a net movement of electric charge through a medium. suppose positive charges are moving through a wire.**
 * Producing Electric Current **
 * A flow of charged particles are called an electric current. The flow of charged particles in an electric current are also called conventional current, the energy can come in either one or two diffferent ways either kenetic energy or potential energy. With potential energy you would need a power source in this case it would be a battery. Energy can come from a variety of different sources, one that we may be familiar with would be, a vltaic or galvanic cell (a common dry cell), converts chemical energy to electric energy. Several galvanic cells connected together are called a battery. A secondary source of electric energy a photovoltaic cell, or solar cell changes light energy into electric energy.**

The most common manifestation of charge in motion is the movement of electrons in a wire such as the wire leading to the computer that is running this lesson. That's one form of current. Here's a simulation that lets you see how charge flows around an electrical circuit through several elements.


 * [[image:http://www.home-lighting-design.com/images/simple-circuit-diagram.gif width="237" height="107" caption="Simple Circuit Diagram"]] ||
 * **A simple circuit diagram.** ||



power: The rate of which energy is transferred

Electric current formula:

Problem & Solution

Current The current in a light bulb is 0.835 a how long does it take for a total charge of 1.67 0 to pass a point in the wire? given: ^Q = 1.67c i= 0.835a unknown: ^t=?

current can be direct or alternating:

There are two diffrent types of current. Direct current alternating current the diffrence between the two types of current is just what their names suggest. In direct current charges move in only one direction of charges continuously changes in the foward and reverse directions. In alternating current the terminals of the source of potential diffrence are constantly changing sign. There is no net motion of the charge carriers in alternating current the simply vibrate back and foth...

Examples: DIRECT CURRENT

ALTERNATING CURRENT

Safety Devices


 * Short ciruit- When too many appliances are turned on at the same time or when a short circuit occurs in one appliance.
 * Fuse- is a short piece of metal that metal that melts when too large a current pased through it.
 * Circuit breaker- is an automatic switch that opens when the currrent reaches a threshold vaule
 * Ground- Fault interrupter- in an electric outlet prevnts such injuries because it cotains an electric circuit that detects small diffrence in current caused by an extra current path and opens the ciruit.

Physics: Conventional current: Charge flow from the higher potential diffrence of B to A through C. This of positve charge.

ConServation of charge: Charge cannot be created or destroyed, but they can be separated. Thus the total amount of charge- the number of negative electrons and positive ions inthe ciruits does not change.

=﻿Questions & Answers=

What do you call it when you have too many appliances plugged in and the power shuts off?

What is a flow of charged particles called?

How does the electric company determine how much electricity a house uses?

What would a material with no resistance be called?

Anytime the current has two or more paths to follow, the connection is labeled what?

If power is measured in watts, energy is measured in what?

What is current measured in?

What is the exact definiton of a conventional current?

What is the difference between a parallel connection and a series connection?