8 th Grade Science Electricity & Magnetism

Name: _______________Teacher: _____________Class Period: __________

Unknown Author is

Georgia Standards of Excellence:

S8P5. Obtain, evaluate, and communicate information about gravity, electricity, and magnetism as major forces acting in nature.

a. Construct an argument using evidence to support the claim that fields (i.e., magnetic fields, gravitational fields, and electric fields) exist between objects exerting forces on each other even when the objects are not in contact.b. Plan and carry out investigations to demonstrate the distribution of charge in conductors and insulators. c. Plan and carry out investigations to identify the factors (e.g., distance between objects, magnetic force produced by an electromagnet with varying number of wire turns, varying number or size of dry cells, and varying size of iron core) that affect the strength of electric and magnetic forces.

Learning Targets:

1. I can support the claim that magnetic fields exist between objects exerting forces on each other even when the objects are not in contact by constructing an argument using the CER Framework.

2. I can support the claim that gravitational fields exist between objects exerting forces on each other even when the objects are not in contact by constructing an argument using the CER Framework.

3. I can support the claim that electric fields exist between objects exerting forces on each other even when the objects are not in contact by constructing an argument using the CER Framework.

4. I can demonstrate the distribution of charge in conductors and insulators by planning and carrying out investigations.

5. I can identify the factors that affect the strength of electric forces by planning and carrying out investigations.

6. I can identify the factors that affect the strength of magnetic forces by planning and carrying out investigations.

Electricity Vocabulary

Word DefinitionLaw of Electric Charges Like charges ___________ and opposite

charges ___________.

Electric Charge A fundamental _________ that leads to the ______________ interactions among particles that make up matter.

Electric Force The _________ between charged objects.

Electric Field The __________ surrounding a charged ____________ or object within which ____________ force affects other charged particles or objects.

Electrical Conductor A _____________ in which charges can move ____________.

Electric Insulator A _____________ in which charges cannot move __________.

Semiconductor A special class of materials that ___________ electric charge better than electrical ____________ but not as well as electrical ______________.

Static Electricity ____________ charge at rest; generally produced by __________ or _________________.

Electric Discharge The ________ movement of excess charge from ________ place to another.

Electric Current The ___________ at which electric charges pass a given point.

Direct Current Charges flow in the __________ direction.

Alternating Current Charges __________ shift from flowing in one direction to flowing in the _________ direction.

Voltage The _________ of work to move a unit electric charge between two points; expressed in _________.

Resistance In physical science, the _________ presented to the current by a material or device.

Ohm’s Law The amount of _______ in a circuit is determined by the ________ supplied and the __________ of the conductor.

Electric Circuit A __________ of electrical components connected such that they provide one or more complete ____________ for the movement of charges.

Series Circuit A __________ in which the parts are ___________ one after another such that the ___________ in each part is the same.

Parallel Circuit A ________ in which the parts are __________ in branches such that the voltage across each part is the ___________.

Electric Charge

_____________________ are _____________ or _____________ and exert _____________ on each other.

How does an _________________ become _________________? ______________ in the objects can ______________ or _________________

__________________. Atom becomes an ____________. Three ways an _______________ can become _____________

o Friction – by ______________ two ______________ together.o _____________________ - __________________ transferred from one

_____________ to another by ________________ contact.o ___________________ - when ___________________ in an

__________________ object are _________________ without ____________ contact.

________________________ - is an _____________ of ______________ charge on an _________________.

_____________________ is the ____________ between _______________ objects. Law of electric charge

o “ ____________ charges ____________ and _______________ charges _______________

The _____________ force between tow charged objects _________________ on the ______________ between them and the ____________ of ______________ on each object.

An _________________________ is the space in which ________________ exert a ____________ on each other.

An ___________________ is a ___________________ in which ________________ _____________ move easily from place to place.

o Examples: ______________, ____________________, _________________ A _________________ is a _________________ in which ________________ CAN

________ easily from place to place.o Example:

____________________________ - the ______________ movement of _____________ _____________ from one place to another.

Electric Current

An __________________________ is the __________ flow of _______________ (electric charge).

Unit of measure for electric current is ___________________ (A) _________________ a _______________ conducting ___________ that _____________

charges ______________ continuously through. ________________ will move away from the ____________ battery terminal tow the

_____________ terminal. ______________________ - the _____________ of _______________ energy in an

____________ current. Unit of measure is __________________ _________________________ the _______________ of how _________________ it is for

__________________ to ________________ through a ____________________. The unit of measure for _________________ is __________________ ( ) The _________________ of ________________ depends on the _____________ the wire is

made of, as well as the __________________ and ______________ of the ____________. ______________ _______________ wire has ______________ resistance. _____________________________ - the amount of _______________ in a circuit is

determined by the ______________ supplied and the __________________ of the conductor.

Voltage ______________- Current _____________ Resistance _________________ - Current __________________ Ohm’s Law = _______________________ ____________ (volts) = _________________ (amps) x ____________________ (ohms)

Applying Ohm’s Law An electric iron plugged into a wall socket has a resistance of 24 Ώ. If the current in the iron

is 5.0 A, what is the voltage provided by the wall socket?

What is the current in a flashlight bulb with a resistance of 30 Ώ if the voltage provided by the flashlight batteries is 3.0V?

What is the resistance of a lightbulb connect to a 110V wall outlet if the current in the lightbulb is 1.0 A?

Electric Circuits

_______________________ consist of three components

o __________________ - provides ______________ (ex: battery)

o _______________ - provides path for ________________

o _________________________ - uses ____________ energy

_____________________ must be ____________ loop in order for _______________ to

_____________. No ___________ in circuit.

____________________ a ____________ with break(s) - ______________ will not

_____________.

Series Circuit

A ____________________ is a ____________ that has only ___________ _____________

for the electric ____________ to ________________.

Series circuit properties

o ______________ is _______________, more ______________ causes ___________

of bulbs.

o _________________ current runs through ___________ devices

o __________ light goes out ____________ lights go out.

Parallel Circuit

A ________________________ is a ____________ that has ____________ than

__________ ____________ for the electric _______________ to __________________.

Parallel circuit properties

o Current _________________ and __________________

o The same ________________ runs through ___________ devices

o If __________ bulb goes ___________, bulbs in ____________ loops stay

____________.

Circuit breaker/fuses

_________________________________ is a _____________ device that __________ wires

in you home from getting too ____________.

_______________________ is a _____________, if a circuit is __________________ and

_____________ gets too _____________ the _____________________________ flips and

_______________ the circuit to stop the flow of _____________. This prevents

________________ from ___________________ and catching ________________.

Electric power

___________________________ is the ____________ at which ___________________

energy is _________________ into other forms of _________________. Measured in

_____________.

______________ (watts) = __________________ (amps) x _________________ (volts)

Cost of _______________________ is determined by the _______________ used and the

amount of ____________ used.

________________ companies sell power in units of __________________________ (kWh)

Determining electric power

The batteries in a portable CD player provide 6.0V. If the current in the CD player is 0.5A,

how much power does the CD player use?

An electric clothes dryer uses 4,400 W of electric power. If the current in the dryer is 20.0A,

what is the voltage?

Circuits

Series Circuit

Parallel Circuit

Magnetism Vocabulary

Word DefinitionMagnet Any ________ that attracts iron or

materials that contain _______.

Magnetic Pole _______ or ________ points, such as the ___________ of a magnetic, that have opposite magnetic qualities.

Magnetic Force The force of __________ or _________ generated by moving or spinning ____________ charges.

Magnetic Field A ____________ where a magnetic force can be ________________.

Domains A __________ group of atoms with their _____________ poles line up in the same direction.

Electromagnetism The _____________ between ___________ and __________________.

Solenoid A _____________ of wire with an electric _______________ in it.

Electromagnet A _________ that has a soft iron core and that acts as a ________ when an electric current is in the coil.

Electric Motor A ____________ that converts _____________ energy into _____________ energy.

Electromagnetic Induction The __________ of creating a current in a circuit by changing the _____________ field.

Electric Generator A ____________ that converts __________

energy into ____________ energy.

Transformer A _________ that increases or decreases the ______________ of an alternating current.

Magnetism and Electricity

Magnets

________________ are objects the ___________ and invisible ______________ called

_____________ force.

o Magnets have _____________ and ____________ poles

o ____________ magnet poles _______________ each other

o ___________ magnet poles ______________ each other.

A ____________________ is the _______________ around a _________________ where

the ________________ force is.. ______________ field is ___________________ at the

_____________.

__________________________ is a large group of _______________ with their

____________________ poles _____________ up in the _____________ direction.

When a ___________________ material comes in contact with a ______________ the

magnetic ________________ will change. Becoming a ______________ magnet.

Electricity and Magnetism

Because _____________ spin as they ______________ they produce a _____________

field.

Therefore when ____________ current flows in a wire, the ____________ is also surrounded

by a _______________ field.

Magnets push and pull currents

_______________________ - the force of a ________________ exerts on a

_______________ carrying wire transforms __________________________ into

___________________________.

Magnets create current

___________________ uses a ________________ field to turn _________________ into

______________________.

In a _________________, a ________________ source _________ a _____________ loop

in a _________________ field. Every half turn the ________________ will

______________ direction, supplying ______________ current.

Use: produce _____________________.

________________________________ a __________________ that _______________

direction.

In a ________________________, _______________ flow in only ___________ direction.

Electricity and Magnetism Study Guide

1. What is a conductor? Examples of good conductors

2. What is an insulator? Examples of good insulators.

3. What is resistance? How does it affect the flow of electricity?

4. What is the unit of measure for resistance?

5. What is a parallel circuit?

6 What is electric power?

7. What is a circuit breaker for?

8. What is a series circuit?

9. What is alternating current? (AC)

10. What is direct current? (DC)

11. What is static charge?

12. Draw electric charges and arrows to show how the electrical charges will interact with each other.

13. What happens to an electric field, as you get closer to a charge? What happens to an electric field as you get farther away from an electric field?14. What is the unit of measure for the sale of electricity by electric companies?

15. What is an electromagnet?

16. What is a circuit?

17. What is voltage?

18. How are objects charged?

19. How do magnets attract other magnetic others?

20, What happens to the atoms in a magnet?

21. Where is the magnetic field the strongest?

23. Identify two ways to increase the magnetic field of an electromagnet?

24. What is Ohm’s Law? What is the equation?

25. How does a generator work?

26. How can you quickly determine whether a string of lights is wired in series or in parallel?27. What is an electric current?

28. When you break a magnet into two pieces what do you get and why?

29. How do you create a temporary magnet?

30. If you used 2000 kWh in one month and the electric company charges .10 kWh, what is your monthly bill?