Unit 6 Section 2 Notes

Static Electricity build-up surface  The build-up of an electric charge on the surface of an object. does not flow.  The charge builds up but does not flow. potential energynot stored  Static electricity is potential energy. It does not move. It is stored.

Current Electricity  Current  Current: The flow of electrons from one place to another. amperes amps (A)  Measured in amperes; Abbreviated amps (A) Kinetic  Current electricity is Kinetic energy

What is an Ampere?

 Where do your see these plugs? Why are they larger? Copyright © 2010 Ryan P. Murphy

 Answer: The Plug to a dryer or stove is much thicker than a standard outlet to account for extra amps. Copyright © 2010 Ryan P. Murphy

 Answer: The Plug to a dryer or stove is much thicker than a standard outlet to account for extra amps. Copyright © 2010 Ryan P. Murphy

How can we control currents? circuits  With circuits.  Circuitis a pathfor the flow of electrons wires  Circuit: is a path for the flow of electrons. We use wires.

There are 2 types of currents:  Direct Current (DC) same  Direct Current (DC) – Where electrons flow in the same direction in a wire. Example: Batteries, Static Electricity, Lightning Example: Batteries, Static Electricity, Lightning

There are 2 types of currents:  Alternating Current (AC) different  Alternating Current (AC) – electrons flow in different directions in a wire; flow is back and forth, changing its direction many times in one second. Example: Plugs and outlets Example: Plugs and outlets

Advantages of AC  Voltage can be raised or lowered.  More efficient over long distances.

Rockin Quiz! This is your chance to rock it out in science class so don’t just sit there. At least rock your head or tap your desk etc. After some intro slides, teacher will call on a student to rock it out on their way to the board. Student goes to board and touches the picture that represents AC or DC on the AC/DC logo (If using a screen just point and drum the air). Student will then pick a new student to go to the board as the teacher changes the slide. Thunderstruck video (For the music during quiz and I didn’t see anything inappropriate ).

 Note: Many devices such as computers plug into the wall (AC Current) but the AC current is converted into DC Current to run through the machine. For simplicity sake in this activity, if it has a plug we will call it AC, and if doesn’t (batteries) we will call it DC.

“DC”

“Its one way!”

“AC”

“It Alternates!”

 Is this (AC) Alternating Current, or (DC) Direct Current?

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 What is Resistance??? This... ???

What is Resistance? opposition heat caused by internal friction  The opposition to the flow of an electric current, producing heat; caused by internal friction greater less  The greater the resistance, the less current gets through.  Goodlow  Good conductors have low resistance. Ohms  Measured in Ohms; Symbol:

The refusal to accept or comply with something; the attempt to prevent something by action or argument.

What Influences Resistance?  Material of wire  Material of wire – aluminum and copper have low resistance  Thickness  Thickness – the thicker the wire the lower the resistance  Length  Length – shorter wire has lower resistance  Temperature  Temperature – lower temperature has lower resistance

What is Voltage? : A measure of the force or pressure under which electricity flows  Volt: A measure of the force or pressure under which electricity flows. greatergreater the force or “pressure”  The greater the voltage, the greater the force or “pressure” that drives the charge through the circuit.

 Electricity flows through a wire much like water flows through a pipe.

A force is required to drive it and resistance to is encountered, the flow of current is measured in amps

Difference between Volts and Amps  Example – you could say that… Ampshow much Amps measure how much water comes out of a hose. Voltshow hard Volts measure how hard the water comes out of a hose.

What are Watts? is a measurement of electrical power created  Watt: is a measurement of electrical power created. one joule of energy per second 1 watt is equal to one joule of energy per second

What are Watts? multiplying volts times amps  A Watt is calculated by multiplying volts times amps. kilowatt hours  Most household electrical usage is billed in kilowatt hours, or the amount of hours times 1,000 watts.

Volts are a measure of the force or pressure under which electricity flows. Amps are a measurement of the current flow rate of electrons Resistance: Anything in an electrical circuit that impedes the flow of current is referred to as resistance. Watts is a measurement of electrical power created. –1 watt is equal to one joule of energy per second.

Volts are a measure of the force or pressure under which electricity flows. Amps are a measurement of the current flow rate of electrons Resistance: Anything in an electrical circuit that impedes the flow of current is referred to as resistance. Watts is a measurement of electrical power created. –1 watt is equal to one joule of energy per second.

Which is the correct description of Watts? This is a measurement of electrical power created. This is a measurement of the current flow rate of electrons This is a measure of the force or pressure under which electricity flows Anything in an electrical circuit that impedes the flow of current.

Which is the correct description of Watts? This is a measurement of electrical power created. This is a measurement of the current flow rate of electrons This is a measure of the force or pressure under which electricity flows Anything in an electrical circuit that impedes the flow of current.

Which is the correct description of Watts? This is a measurement of electrical power created. This is a measurement of the current flow rate of electrons This is a measure of the force or pressure under which electricity flows Anything in an electrical circuit that impedes the flow of current.

Which is the correct description of Watts? This is a measurement of electrical power created. This is a measurement of the current flow rate of electrons This is a measure of the force or pressure under which electricity flows Anything in an electrical circuit that impedes the flow of current.

Which is the correct description of Watts? This is a measurement of electrical power created. This is a measurement of the current flow rate of electrons This is a measure of the force or pressure under which electricity flows Anything in an electrical circuit that impedes the flow of current.

Which is the correct description of Watts? This is a measurement of electrical power created. This is a measurement of the current flow rate of electrons This is a measure of the force or pressure under which electricity flows Anything in an electrical circuit that impedes the flow of current.

Which is the correct description of Watts? This is a measurement of electrical power created. This is a measurement of the current flow rate of electrons This is a measure of the force or pressure under which electricity flows Anything in an electrical circuit that impedes the flow of current.

Which is the correct description of Watts? This is a measurement of electrical power created. This is a measurement of the current flow rate of electrons This is a measure of the force or pressure under which electricity flows Anything in an electrical circuit that impedes the flow of current.

Which is the correct description of Watts? This is a measurement of electrical power created. This is a measurement of the current flow rate of electrons This is a measure of the force or pressure under which electricity flows Anything in an electrical circuit that impedes the flow of current.

Which is the correct description of Watts? This is a measurement of electrical power created. This is a measurement of the current flow rate of electrons Anything in an electrical circuit that impedes the flow of current. This is a measure of the force or pressure under which electricity flows

Volts are a measure of the force or pressure under which electricity flows. Amps are a measurement of the current flow rate of electrons Resistance: Anything in an electrical circuit that impedes the flow of current is referred to as resistance. Watts is a measurement of electrical power created. –1 watt is equal to one joule of energy per second.

Volts are a measure of the force or pressure under which electricity flows. Amps are a measurement of the current flow rate of electrons Resistance: Anything in an electrical circuit that impedes the flow of current is referred to as resistance. Watts is a measurement of electrical power created. –1 watt is equal to one joule of energy per second.

Which is the correct description of Watts? This is a measurement of the current flow rate of electrons Anything in an electrical circuit that impedes the flow of current. This is a measure of the force or pressure under which electricity flows This is a measurement of electrical power created.

Which is the correct description of Watts? This is a measurement of the current flow rate of electrons Anything in an electrical circuit that impedes the flow of current. This is a measure of the force or pressure under which electricity flows This is a measurement of electrical power created.

Which is the correct description of Watts? This is a measurement of the current flow rate of electrons Anything in an electrical circuit that impedes the flow of current. This is a measure of the force or pressure under which electricity flows This is a measurement of electrical power created.

Which is the correct description of Watts? This is a measurement of the current flow rate of electrons Anything in an electrical circuit that impedes the flow of current. This is a measure of the force or pressure under which electricity flows This is a measurement of electrical power created.

Which is the correct description of Watts? This is a measurement of the current flow rate of electrons Anything in an electrical circuit that impedes the flow of current. This is a measure of the force or pressure under which electricity flows This is a measurement of electrical power created.

Which is the correct description of Watts? This is a measurement of the current flow rate of electrons Anything in an electrical circuit that impedes the flow of current. This is a measure of the force or pressure under which electricity flows This is a measurement of electrical power created.

Which is the correct description of Watts? This is a measurement of the current flow rate of electrons Anything in an electrical circuit that impedes the flow of current. This is a measure of the force or pressure under which electricity flows This is a measurement of electrical power created.

Which is the correct description of Watts? This is a measurement of the current flow rate of electrons Anything in an electrical circuit that impedes the flow of current. This is a measure of the force or pressure under which electricity flows This is a measurement of electrical power created.

Which is the correct description of Watts? This is a measurement of the current flow rate of electrons Anything in an electrical circuit that impedes the flow of current. This is a measure of the force or pressure under which electricity flows This is a measurement of electrical power created.

 Georg Simon Ohm (1789 –1854) direct voltage electric current Ohm found that there is a direct proportionality between voltage applied across a conductor and the resultant electric current. Learn more at.. m/vol_1/chpt_2/1.html

The measure of resistance in a circuit to the flow of an electric current  Ohms: The measure of resistance in a circuit to the flow of an electric current. The greater the ohm value the more difficult it is for current to flow through a given circuit. A low ohm value represents a low resistance and the easy flow of current through a circuit Current

The measure of resistance in a circuit to the flow of an electric current  Ohms: The measure of resistance in a circuit to the flow of an electric current. greatermore difficult The greater the ohm value the more difficult it is for current to flow through a given circuit. low ohm low resistance A low ohm value represents a low resistance and the easy flow of current through a circuit.

 Ohms Law Simulator at…

 If 220 volts travel through a copper wire and the current is 36A, What’s the resistance of the wire?

 If 220 volts travel through a copper wire and the current is 36A, What’s the resistance of the wire?

 If 220 volts travel through a copper wire and the current is 36A, What’s the resistance of the wire?

 If 220 volts travel through a copper wire and the current is 36A, What’s the resistance of the wire?

 If 220 volts travel through a copper wire and the current is 36A, What’s the resistance of the wire? V 220 V R= I

 If 220 volts travel through a copper wire and the current is 36A, What’s the resistance of the wire? V 220 V R= = I 36 A

 If 220 volts travel through a copper wire and the current is 36A, What’s the resistance of the wire? V 220 R= = 6.1 ohms I 36A

 If 220 volts travel through a copper wire and the current is 36A, What’s the resistance of the wire? V 220 R= = 6.1 ohms I 36A

 A Rude Monkey decided to stick his tongue to a 120 V outlet with 50,000 ohms of resistance. How much current will he experience? V 120 V I = =.0024A R 50,000 ohms

 A Rude Monkey decided to stick his tongue to a 120 V outlet with 50,000 ohms of resistance. How much current will he experience?

 A Rude Monkey decided to stick his tongue to a 120 V outlet with 50,000 ohms of resistance. How much current will he experience?

 A Rude Monkey decided to stick his tongue to a 120 V outlet with 50,000 ohms of resistance. How much current will he experience? V 120 V I = =.0024A R

 A Rude Monkey decided to stick his tongue to a 120 V outlet with 50,000 ohms of resistance. How much current will he experience? V 120 V I = =.0024A R 50,000 ohms

 A Rude Monkey decided to stick his tongue to a 120 V outlet with 50,000 ohms of resistance. How much current will he experience? V 120 V I = =.0024A R 50,000 ohms

 A Rude Monkey decided to stick his tongue to a 120 V outlet with 50,000 ohms of resistance. How much current will he experience? V 120 V I = =.0024A R 50,000 ohms

 A Rude Monkey decided to stick his tongue to a 120 V outlet with 50,000 ohms of resistance. How much current will he experience? V 120 V I = =.0024A R 50,000 ohms

 Video Link! Current, Voltage, Resistance