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

CURRENTUnit 6 Section 2 Notes

Static Electricity

The build-up of an electric charge on the surface of an object.

The charge builds up but does not flow.

Static electricity is potential energy. It does not move. It is stored.

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http://www.google.com/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRw&url=http://www.howdyhonda.com/blog/dear-static-electricity-i-hate-you/&ei=VHPfVIfKEcGqNvS2gKAH&bvm=bv.85970519,d.eXY&psig=AFQjCNFD_7KFuWbqm_WjcbCczwW5OwITww&ust=1424016506787026

Current Electricity

Current: The flow of electrons from one place to another.

Measured in amperes; Abbreviated amps (A)

Current electricity is Kinetic energy

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What is an Ampere?

Ampere: a measurement of the current flow rate of electrons.Basically, the larger the size of wire, the

greater the ampere capacity.

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.


Answer: The Plug to a dryer or stove is much thicker than a standard outlet to account for extra amps.


How can we control currents? With circuits. Circuit: is a path for the

flow of electrons. We use wires.

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There are 2 types of currents: Direct Current (DC) – Where

electrons flow in the same direction in a wire.Example: Batteries , Static Electricity,

Lightning

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There are 2 types of currents: 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

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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 ).http://www.youtube.com/watch?v=v2AC41dglnM

http://www.youtube.com/watch?v=v2AC41dglnM

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?
























?












What is Resistance??? This... ???

What is Resistance?

The opposition to the flow of an electric current, producing heat; caused by internal friction

The greater the resistance, the less current gets through.

Good conductors have low resistance.

Measured in Ohms; Symbol:

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

Resistance

What Influences Resistance? Material of wire – aluminum and

copper have low resistance Thickness – the thicker the wire

the lower the resistance Length – shorter wire has lower

resistance Temperature – lower temperature

has lower resistance

What is Voltage? Volt: A measure of the force or

pressure under which electricity flows. 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.

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…Amps measure how much

water comes out of a hose.Volts measure how hard the

water comes out of a hose.

What are Watts?

Watt: is a measurement of electrical power created.1 watt is equal to one joule of energy per

second

What are Watts? A Watt is calculated by multiplying

volts times amps. 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.

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Which is the correct description of Watts?

AThis is a measurement of electrical power created.

This is a measurement of the current flow rate of electrons

B CThis is a measure of the force or pressure under which electricity flows

DAnything in an electrical circuit that impedes the flow of current.










Watts






Watts






Watts


Resistance





Watts


Resistance





AmpsWatts


Resistance





AmpsWatts


Resistance





Amps VoltsWatts


Resistance




B C

AmpsVoltsWatts


Resistance

This is a measure of the force or pressure under which electricity flows

Volts

Again!





Study

for 3

0 S






AThis is a measurement of the current flow rate of electrons

B C

Volts



This is a measurement of electrical power created.



B C

Volts






B C

AmpsVolts






B C

AmpsVolts






B C

AmpsVolts



Resistance




B C

AmpsVolts



Resistance




B C

AmpsVolts



VoltsResistance




B C

AmpsVolts



VoltsResistance




B C

AmpsVolts



VoltsResistance


Watts

Georg Simon Ohm (1789 –1854) Ohm found that there is a direct proportionality

between voltage applied across a conductor and the resultant electric current.

Learn more at.. http://www.allaboutcircuits.com/vol_1/chpt_2/1.html

http://www.allaboutcircuits.com/vol_1/chpt_2/1.html

http://www.allaboutcircuits.com/vol_1/chpt_2/1.html

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

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.

Ohm’s Law

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Ohms Law Simulator at…http://phet.colorado.edu/en/simulation/ohms-law

I

http://phet.colorado.edu/en/simulation/ohms-law

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


V 220 V

R= ------ --------- =

I 36 A


V 220

R= ------ --------- = 6.1 ohms

I 36A


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




V 120 V

I = ----- ----------- = .0024A

R


V 120 V

I = ----- ----------- = .0024A

R 50,000 ohms


V 120 V

I = ----- ----------- = .0024A

R 50,000 ohms


V 120 V

I = ----- ----------- = .0024A

R 50,000 ohms


V 120 V

I = ----- ----------- = .0024A

R 50,000 ohms

Video Link! Current, Voltage, Resistancehttp://www.youtube.com/watch?v=J4Vq-xHqUo8

http://www.youtube.com/watch?v=J4Vq-xHqUo8

Documents

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