Chapter 20: Electricity Section 20.1: Electric Charge and Static Electricity I. Electric Charge Group #_____ Main Idea: Drawing_________________ II. Electric Forces Group #_____ Main Idea: Drawing_________________ III. Electric Fields Group #_____ Main Idea: Drawing_________________ IV. Static Electricity and Charging Group #_____ Main Idea: Drawing_________________ A. Charging by Friction Group #_____ Main Idea: Drawing_________________ B. Charging by Contact Group #_____ Main Idea: Drawing_________________ C. Charging by Induction Group #_____ Main Idea: Drawing_________________ V. Static Discharge Group #_____ Main Idea: Drawing_________________ Section 20.2: Electric Current and Ohm’s Law I. Electric Current Group #_____ Main Idea: Drawing_________________ II. Conductors and Insulators Group #_____ Main Idea: Drawing_________________ III. Resistance Group #_____ Main Idea: Drawing_________________ IV. Voltage Group #_____ Main Idea: Drawing_________________ A. Potential Difference Group #_____ Main Idea:
Transcript
Chapter 20: Electricity Section 20.1: Electric Charge and Static Electricity
I. Electric Charge Group #_____
Main Idea:
Drawing_________________
II. Electric Forces Group #_____
Main Idea:
Drawing_________________
III. Electric Fields Group #_____
Main Idea:
Drawing_________________
IV. Static Electricity and Charging Group #_____
Main Idea:
Drawing_________________
A. Charging by Friction Group #_____
Main Idea:
Drawing_________________
B. Charging by Contact Group #_____
Main Idea:
Drawing_________________
C. Charging by Induction Group #_____
Main Idea:
Drawing_________________
V. Static Discharge Group #_____
Main Idea:
Drawing_________________
Section 20.2: Electric Current and Ohm’s Law
I. Electric Current Group #_____
Main Idea:
Drawing_________________
II. Conductors and Insulators Group #_____
Main Idea:
Drawing_________________
III. Resistance Group #_____
Main Idea:
Drawing_________________
IV. Voltage Group #_____
Main Idea:
Drawing_________________
A. Potential Difference Group #_____
Main Idea:
Drawing_________________
B. Voltage Sources Group #_____
Main Idea:
Drawing_________________
V. Ohm’s Law Group #_____
Main Idea:
Drawing_________________
Section 20.3: Electric Circuits
I. Circuit Diagrams Group #_____
Main Idea:
Drawing_________________
II. Series Circuits Group #_____
Main Idea:
Drawing_________________
III. Parallel Circuits Group #_____
Main Idea:
Drawing_________________
IV. Power and Energy Calculations Group #_____
Main Idea:
Drawing_________________
V. Electrical Safety Group #_____
Main Idea:
Drawing_________________
A. Home Safety Group #_____
Main Idea:
Drawing_________________
B. Personal Safety Group #_____
Main Idea:
Drawing_________________
Section 20.4: Electronic Devices
I. Electronic Signals Group #_____
Main Idea:
Drawing_________________
A. Analog Signals Group #_____
Main Idea:
Drawing_________________
B. Digital Signals Group #_____
Main Idea:
Drawing_________________
II. Vacuum Tubes Group #_____
Main Idea:
Drawing_________________
III. Semiconductors Group #_____
Main Idea:
Drawing_________________
IV. Solid-State Components Group #_____
Main Idea:
Drawing_________________
A. Diodes Group #_____
Main Idea:
Drawing_________________
B. Transistors Group #_____
Main Idea:
Drawing_________________
C. Integrated Circuits Group #_____
Main Idea:
Drawing_________________
V. Communications Technology Group #_____
Main Idea:
Drawing_________________
Chapter 21: Magnetism Section 21.1: Magnet’s and Magnetic Fields
I. Magnetic Forces Group #_____
Main Idea:
Drawing_________________
II. Magnetic Fields Group #_____
Main Idea:
Drawing_________________
A. Magnetic Fields Around Magnets Group #_____
Main Idea:
Drawing_________________
B. Magnetic Field Around Earth Group #_____
Main Idea:
Drawing_________________
III. Magnetic Materials Group #_____
Main Idea:
Drawing_________________
A. Nonmagnetized Materials Group #_____
Main Idea:
Drawing_________________
B. Magnetized Materials Group #_____
Main Idea:
Drawing_________________
Section 21.2: Electromagnetism
I. Electricity and Magnetism Group #_____
Main Idea:
Drawing_________________
A. Magnetic Fields Around Moving Charges Group #_____
Main Idea:
Drawing_________________
B. Forces Acting on Moving Charges Group #_____
Main Idea:
Drawing_________________
II. Solenoids and Electromagnets Group #_____
Main Idea:
Drawing_________________
III. Electromagnetic Devices Group #_____
Main Idea:
Drawing_________________
A. Galvanometers Group #_____
Main Idea:
Drawing_________________
B. Electric Motors Group #_____
Main Idea:
Drawing_________________
C. Loudspeakers Group #_____
Main Idea:
Drawing_________________
Section 21.3: Electrical Energy Generation and Transmission
I. Generating Electric Current Group #_____
Main Idea:
Drawing_________________
II. Generators Group #_____
Main Idea:
Drawing_________________
A. AC Generators Group #_____
Main Idea:
Drawing_________________
B. DC Generators Group #_____
Main Idea:
Drawing_________________
III. Transformers Group #_____
Main Idea:
Drawing_________________
A. Why Transformers are Needed Group #_____
Main Idea:
Drawing_________________
B. Changing Voltage and Current Group #_____
Main Idea:
Drawing_________________
C. Types of Transformers Group #_____
Main Idea:
Drawing_________________
IV. Electrical Energy for your Home Group #_____
Main Idea:
Drawing_________________
V. The Rock Cycle Group #_____
Main Idea:
Drawing_________________
Name ___________________________ Class ___________________ Date _____________
Chapter 20 Electricity
Physical Science Reading and Study Workbook ■ Chapter 20 239
Section 20.1 Electric Charge and Static Electricity (pages 600–603)This section explains how electric charge is created and how positive andnegative charges affect each other. It also discusses the different ways thatelectric charge can be transferred.
Reading Strategy (page 600)
Identifying Main Ideas Copy the table on a separate sheet of paper.As you read, write the main ideas. For more information on thisReading Strategy, see the Reading and Study Skills in the Skills andReference Handbook at the end of your textbook.
Characteristics of Electric Charge
Topic Main Idea
Electric Charge An excess or shortage of electrons produces a net electric charge.
Electric Forces
Electric Fields
Static Electricity
Electric Charge (pages 600–601)
1. What are the two types of electric charge? a. b.
2. Is the following sentence true or false? In an atom, negativelycharged electrons surround a positively charged nucleus.
3. Is the following sentence true or false? If a neutral atom gains one ormore electrons, it becomes a positively charged ion.
4. What is the SI unit of electric charge?
Electric Forces (page 601)
5. Circle the letter of each sentence that is true about electric force.a. Like charges attract and opposite charges repel.b. Electric force is the attraction or repulsion between electrically
charged objects.c. Electric force is inversely proportional to the amount of charge.d. Electric force is inversely proportional to the square of the
distance between two charges.
Like charges repel and opposite charges attract.
The strength of a field depends on the net charge and distance from the charge.
Charge can be transferred by friction, contact, and induction.
NegativePositive
true
false
The coulomb
Name ___________________________ Class ___________________ Date _____________
Chapter 20 Electricity
240 Physical Science Reading and Study Workbook ■ Chapter 20
6. Which are stronger inside an atom, electric forces or gravitationalforces?
7. Is the following sentence true or false? Electric forces cause frictionand other contact forces.
Electric Fields (page 602)
8. A charge’s electric field is the effect the charge has onin the space around it.
9. Circle the letters of the factors that the strength of an electric fielddepends on.a. the direction of the fieldb. whether the charge is positive or negativec. the amount of charge that produces the fieldd. the distance from the charge
10. Is the following sentence true or false? The field of a negativecharge points away from the charge.
Static Electricity and Charging (pages 602–603)
11. Static electricity is the study of the .12. Is the following sentence true or false? Charge can be transferred
by friction, by contact, and by induction. 13. What is the law of conservation of charge?
14. Rubbing a balloon on your hair is an example of charging by.
15. A charge transfer between objects that touch each other is called.
16. Circle the letter of each sentence that is true about charging.a. When you rub a balloon on your hair, your hair loses electrons
and becomes positively charged.b. The sphere of a Van de Graaff generator transfers all of its
charge to you when you touch it.c. Induction occurs when charge is transferred without contact
between materials.d. Static charges cannot move.
Static Discharge (page 603)
17. Is the following sentence true or false? Static discharge occurswhen a pathway through which charges can move formssuddenly.
18. How does lightning occur?
Electric forces are stronger.
true
other charges
false
behavior of electric charges
The total charge in an isolated system
is constant.
true
friction
charging by contact
true
Negative charge in the lower part of a storm cloud induces a
positive charge in the ground below the cloud. Eventually the air becomes charged, forming a
pathway for the electrons to travel from the cloud to the ground.
Name ___________________________ Class ___________________ Date _____________
Chapter 20 Electricity
Physical Science Reading and Study Workbook ■ Chapter 20 241
Section 20.2 Electric Current and Ohm’s Law (pages 604–607)This section discusses electric current, resistance, and voltage. It also usesOhm’s Law to explain how voltage, current, and resistance are related.
Reading Strategy (page 604)
Predicting Before you read, write a prediction of what electric current isin the table below. After you read, if your prediction was incorrect orincomplete, write what electric current actually is. For more informationon this Reading Strategy, see the Reading and Study Skills in the Skillsand Reference Handbook at the end of your textbook.
Electric Current
Electric Current Electric Current Probably Means Actually Means
Electric Current (page 604)
1. What is electric current?
2. Complete the following table about electric current.
Electric Current
Type of Current How Charge Flows Examples
Direct
Alternating Two directions
3. Electrons flow in the wire from a(n) terminalto a(n) terminal.
Conductors and Insulators (page 605)
4. What is an electrical conductor?
5. What is an electrical insulator?
6. Is the following sentence true or false? Metals are good conductorsbecause they do not have freely moving electrons.
Sample answer: Current is moving charge. Electric current is a continuous flow of charge.
One direction Flashlight
Home or school
Electric current is a continuous flow of charge.
negativepositive
An electrical conductor is material through which
charge can easily flow.
An electrical insulator is material through which charge
cannot easily flow.
false
Name ___________________________ Class ___________________ Date _____________
Chapter 20 Electricity
242 Physical Science Reading and Study Workbook ■ Chapter 20
Section 20.3 Electric Circuits (pages 609–613)This section describes circuit diagrams and types of circuits. It also explainscalculation of electric power and electric energy and discusses electrical safety.
Reading Strategy (page 609)
Relating Text and Visuals As you read about household circuits,complete the table by listing three things the diagram in Figure 13helps you understand about circuits. For more information on thisReading Strategy, see the Reading and Study Skills in the Skills andReference Handbook at the end of your textbook.
Understanding a Circuit Diagram
What Can Be Seen in the Circuit Diagram?
Wire bringing current from outside
Circuit Diagrams (pages 609–610)
1. Circuit diagrams use to represent parts of acircuit, including a source of electrical energy and devices that arerun by the electrical energy.
Match each symbol to what it indicates on a circuit diagram.Symbol What Symbol Indicates
2. �
3. �
4.
Series Circuits (page 610)
5. Is the following sentence true or false? In a series circuit, if oneelement stops functioning, then none of the elements can operate.
6. Explain why the bulbs shine less brightly when more bulbs are added to a series circuit.
Parallel Circuits (page 610)
7. Is the following sentence true or false? Circuits in a home are rarelywired in parallel.
8. If one element stops functioning in a parallel circuit, the rest of theelements .
a. The direction of currentb. A negative terminalc. A positive terminal
symbols
c
b
a
true
Adding more bulbs increases the resistance, which decreases
the current.
false
can still operate
Grounding wire
Separate circuit for the lights
Separate circuit for the dryer
Name ___________________________ Class ___________________ Date _____________
Chapter 20 Electricity
244 Physical Science Reading and Study Workbook ■ Chapter 20
9. The rate at which electrical energy is converted to another form ofenergy is called .
10. The SI unit of electric power is the joule per second, or, which is abbreviated .
11. Is the following sentence true or false? Electric power is calculatedby multiplying current times voltage.
12. Write the formula for calculating electrical energy.
13. The unit of energy usually used by electric power companies is the.
Electrical Safety (pages 612–613)
14. Circle the letters of what could happen if the current in a wireexceeds the circuit’s safety limit.a. The wire could overheat. b. The wire could get cooler.c. A fire could start. d. A fuse could blow.
15. Explain how a fuse prevents current overload in a circuit.
16. A switch that opens to prevent overloads when current in a circuitis too high is called a(n) .
17. Explain why touching an electrical device with wet hands is dangerous.
18. Is the following sentence true or false? A ground-fault circuitinterrupter shuts down the circuit if the current flowing throughthe circuit and current returning to ground are equal.
19. The transfer of excess charge through a conductor to Earth is called.
20. Complete the following table about equipment used to preventelectrical accidents.
Equipment to Equipment to Equipment toPrevent Current Protect People Prevent ShortOverload from Shock Circuits
a. b. e.
Circuit breaker c.
Grounding wire
d.
Insulation InsulationFuse
Three-prong plug
Ground-faultcircuit interrupter
electric power
Wwatt
true
kilowatt-hour
E � P � t
A wire in the center of the
fuse melts, which stops the flow of charge in the circuit.
circuit breaker
Your hands conduct electricity more readily when they are wet.
false
grounding
Name ___________________________ Class ___________________ Date _____________
Chapter 20 Electricity
Physical Science Reading and Study Workbook ■ Chapter 20 245
Section 20.4 Electronic Devices (pages 618–622)This section discusses how various electronic devices operate and what theyare used for.
Reading Strategy (page 618)
Summarizing Copy the table on a separate sheet of paper. As youread, complete the table to summarize what you learned about solid-state components. For more information on this Reading Strategy, seethe Reading and Study Skills in the Skills and Reference Handbookat the end of your textbook.
Solid–State Components
Solid-State Component Description Uses
Diode
Transistor
Integrated Circuit
Electronic Signals (pages 618–619)
Match each term to its definition.Definition Term
1. Information sent as patterns in the controlled flow of electrons through a circuit
2. The science of using electric currentto process or transmit information
3. A smoothly varying signal produced by continuously changing the voltage or current in a circuit
4. A signal that encodes information as a string of 1’s and 0’s
5. Which type of signal is usually used by an AM radio station?
6. Is the following sentence true or false? Analog signals are morereliable than digital signals.
Electrons flow from an n-type to a p-typesemiconductor.
Change alternating current to direct current
A small current flows throughthe middle layer of three layersof semiconductors, changingthe resistance.
Switch, amplifier
A thin slice of silicon thatcontains many solid-statecomponents
Mobile phones, pagers,computers
a. electronics b. analog signalc. electronic signal d. digital signal
c
a
b
d
Analog signals are used by AM radio stations.
false
Name ___________________________ Class ___________________ Date _____________
Chapter 20 Electricity
246 Physical Science Reading and Study Workbook ■ Chapter 20
7. Circle the letter of each item that is true about vacuum tubes.a. can change alternating current to direct currentb. never burn outc. can increase the strength of a signald. can turn a current on or off
8. Is the following sentence true or false? An image is produced in aCRT when phosphors glow red, green, and blue in response toelectron beams.
Semiconductors (page 621)
9. What is a semiconductor?
10. Name the two types of semiconductors.a. b.
11. Circle the letter of each sentence that is true about a p-typesemiconductor.a. It can be made by adding a trace amount of boron to a silicon.b. Electrons are attracted to positively charged holes at each
boron atom.c. As the electrons jump from hole to hole, it looks like a flow of
positive charge.d. Boron atoms provide weakly bound electrons that can flow.
12. Is the following sentence true or false? In an n-type semiconductor, weakly bound electrons can conduct a current.
Solid-State Components (pages 621–622)
Match each term to its definition.Term Definition
13. diode14. transistor15. integrated circuit
16. A chip or microchip is another name for a(n) .
Communications Technology (page 622)
17. Why is it useful for communication devices to use microchips?
18. A mobile phone can store data such as phone numbers because.
a. A solid-state component with three layers ofsemiconductors
b. A thin slice of silicon that contains manysolid-state components
c. A solid-state component that combines an n-type and p-type semiconductor
true
A semiconductor is a crystalline solid that conducts current
only under certain conditions.
p-type n-type
true
c
a
b
integrated circuit
Microchips make
them more portable, reliable, and affordable.
capacitors store electric charge
Name ___________________________ Class ___________________ Date _____________
Chapter 21 Magnetism
Section 21.1 Magnets and Magnetic Fields (pages 630–633)This section describes magnetic forces and magnetic fields. Characteristics ofmagnetic materials also are discussed.
Reading Strategy (page 630)
Using Prior Knowledge Before you read, copy the diagram below and add what you already know about magnets to the diagram. Afteryou read, revise the diagram based on what you learned. For moreinformation on this Reading Strategy, see the Reading and Study Skillsin the Skills and Reference Handbook at the end of your textbook.
1. In the year 1600, William Gilbert published a book explaining theproperties of .
Magnetic Forces (page 630)
2. Is the following sentence true or false? Magnetic force can beexerted on moving charges, as well as on iron or on another magnet.
3. What did William Gilbert discover when he used a compass to map forces around a magnetic sphere?
4. Circle the letter of each sentence that is true about magnetic force.a. Two magnets that approach each other may attract or repel.b. Magnetic forces do not vary with distance.c. Opposite magnetic poles repel one another.d. Magnetic forces act over a distance.
Physical Science Reading and Study Workbook ■ Chapter 21 251
a. ferromagnetic materialb. magnetic domainc. nonmagnetized material
The field in the gap between the magnets is very
strong, where field lines are close together.
Opposite poles will attract.
magnetosphere
a
c
b
Heat, a jarring impact, or moving a material relative to a magnet can cause realignment of
magnetic domains.
Name ___________________________ Class ___________________ Date _____________
Chapter 21 Magnetism
Section 21.2 Electromagnetism(pages 635–639)This section describes how electricity and magnetism are related. Uses ofsolenoids and electromagnetic devices are discussed, and a description of how these devices work is presented.
Reading Strategy (page 635)Identifying Main Ideas Copy the table on a separate sheet of paper.As you read, write the main idea of the text that follows each topic inthe table. For more information on this Reading Strategy, see theReading and Study Skills in the Skills and Reference Handbook atthe end of your textbook.
Electromagnetism
Topic Main Idea
Electricity and magnetism
Direction ofmagnetic fields
Direction ofelectric currents
Solenoids andelectromagnets
Electromagnetic devices
1. In 1820 Hans Oersted discovered a connection between electricityand .
Electricity and Magnetism (pages 635–636)
2. Electricity and magnetism are different aspects of a single forceknown as the force.
3. Both aspects of the electromagnetic force are caused by.
4. Is the following sentence true or false? Moving electric chargescreate a magnetic field.
5. Is the following sentence true or false? The vibrating charges thatproduce an electromagnetic wave also create a magnetic field.
6. A charge moving in a magnetic field will be deflected in a directionthat is to both the magnetic field and to thevelocity of the charge.
Physical Science Reading and Study Workbook ■ Chapter 21 253
Electricity and magnetism are different aspects of a single forceknown as the electromagnetic force.
Moving charges create a magnetic field.
A charge moving in a magnetic field will be deflected in a directionperpendicular to both the magnetic field and the velocity of the charge.
Changing the current in an electromagnet controls the strength anddirection of its magnetic field.
Electromagnetic devices such as galvanometers, electric motors, andspeakers change electrical energy into mechanical energy.
magnetism
electromagnetic
electric charges
true
true
perpendicular
Solenoids and Electromagnets (pages 637–638)
7. Is the following sentence true or false? The strength of themagnetic field through the center of a coil of current-carrying wireis calculated by adding together the fields from each turn of thecoil.
8. A coil of current-carrying wire that produces a magnetic field iscalled a(n) .
9. What is an electromagnet?
10. Circle the letter of each sentence that is true about electromagnets.a. Placing an iron rod in a solenoid reduces the strength of its
magnetic field.b. Devices that utilize electromagnets include doorbells and
telephones.c. A magnetic field can be turned on and off with an
electromagnet.d. An electromagnet can control the direction of a magnetic field.
11. List three factors that determine the strength of an electromagnet. a.b.c.
12. Is the following sentence true or false? Decreasing the current inthe solenoid decreases the strength of an electromagnet.
13. What types of solenoid cores make stronger electromagnets?
Electromagnetic Devices (pages 638–639)
14. Electromagnetic devices change energy intoenergy.
15. Complete the following table about electromagnetic devices.
Description Device
Uses electromagnets to convert electrical signals into sound waves
Electric motor
Uses an electromagnet to measure small amounts of current
Name ___________________________ Class ___________________ Date _____________
Chapter 21 Magnetism
254 Physical Science Reading and Study Workbook ■ Chapter 21
An electromagnet is a solenoid with a core made of
ferromagnetic material.
Type of ferromagnetic core
Number of turns in the solenoid coil
Current in the solenoid
true
Cores that are easily
magnetized, such as “soft” iron, make stronger electromagnets.
electricalmechanical
Uses a rotating electromagnet to turn an axle
Name ___________________________ Class ___________________ Date _____________
Chapter 21 Magnetism
Section 21.3 Electrical EnergyGeneration and Transmission (pages 642–647)This section describes how electricity is generated and transmitted for humanuse. A description of how generators and transformers function is given.
Reading Strategy (page 642)
Sequencing As you read the section, complete the flowchart to showhow a step-up transformer works. Then make a similar flowchart for astep-down transformer. For more information on this ReadingStrategy, see the Reading and Study Skills in the Skills andReference Handbook at the end of your textbook.
Step-up Transformers
Generating Electric Current (pages 642–643)
1. Is the following sentence true or false? A magnetic field can be usedto produce an electric current.
2. Circle the letter for the name of the process of generating a currentby moving an electrical conductor relative to a magnetic field.a. electromagnetic forceb. electromagnetic fieldc. electromagnetic inductiond. electromagnetic conduction
3. Electrical charges can easily flow through materials known as.
4. Why is the discovery of electromagnetic induction significant?
5. According to Faraday’s law, electric current can be induced in aconductor by .
6. Is the following sentence true or false? Moving a magnet relative toa coil of wire induces a current in the wire if the coil is part of acomplete circuit.
Physical Science Reading and Study Workbook ■ Chapter 21 255
8. Circle the letter that best describes how most of the electricalenergy used in homes and businesses is produced.a. with DC generatorsb. using AC generators at large power plantsc. with small magnets moving inside coilsd. by rotating a magnetic field around a coil of wire
9. Is the following sentence true or false? In an alternating currentproduced by an AC generator, the flow direction of chargesswitches back and forth.
10. Circle the letter of each sentence that is true about generators.a. Small generators can produce enough electricity for a small
business.b. DC generators produce current that flows back and forth.c. Small generators are available for purchase by the public.d. Most modern power plants use DC generators.
Transformers (pages 644–645)
11. A device that increases or decreases voltage and current of twolinked AC circuits is called a(n) .
12. How does a transformer change voltage and current?
13. Why are transformers necessary for home electrical service?
14. Is the following sentence true or false? To prevent overheatingwires, voltage is decreased for long-distance transmission.
15. How is voltage calculated in a transformer?
16. Is the following sentence true or false? A step-down transformerdecreases voltage and increases current.
Electrical Energy for Your Home (pages 646–647)
17. Name at least three sources used to produce electrical energy in the United States.
18. A device with fanlike blades that can convert energy from varioussources into electrical energy is called a(n) .
Name ___________________________ Class ___________________ Date _____________
Chapter 21 Magnetism
256 Physical Science Reading and Study Workbook ■ Chapter 21
