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Science: Topics Electromagnetism (view source)
Revision as of 11:31, 24 August 2012
, 11:31, 24 August 2012no edit summary
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−The following note is a background document for
−teachers. It summarises the things we will need to know. This note is
−meant to be a ready reference for the teacher to develop the concepts
−in electricity and magnetism from Class 6 onwards to Class 10.
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'''Scope of this
+'''Scope of this document'''
−document'''
−The following note is a background document for teachers. It summarises the things we will need to know. This note is meant to be a ready reference for the teacher to develop the concepts in electricity and magnetism from Class 6 onwards to Class 10.
This document attempts to cover all the topics
+This document attempts to cover all the topics identified in the concept map. To plan the actual lessons, the teacher must use this in connection with the theme plan.
−identified in the concept map. To plan the actual lessons, the
−teacher must use this in connection with the theme plan.
−= Concept Map =
= Concept Map =
[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_17376afb.jpg]]
−|
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'''CONCEPT
'''CONCEPT
−DEVELOPMENT'''
DEVELOPMENT'''
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Charges,
Charges,
− static electricity, electric current,<br>
+ static electricity, electric current,
conductors, insulators,
conductors, insulators,
simple circuits
simple circuits
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1.The
1.The
− students recall the two types of charges.<br>
+ students recall the two types of charges.
2.The students
2.The students
− recognise the accumulation of charges in the activity,<br>
+ recognise the accumulation of charges in the activity,
3.The
3.The
students can recognise the necessity of a condctor to the flow of
students can recognise the necessity of a condctor to the flow of
− charges.<br>
+ charges.
4.The students can differentiate between conductors
4.The students can differentiate between conductors
and insulators.
and insulators.
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1.The
1.The
− students can perform activities to accumulate charges.<br>
+ students can perform activities to accumulate charges.
2. They
2. They
can identify the conductors and insulators in the given
can identify the conductors and insulators in the given
− materials<br>
+ materials
3.They can draw the diagrams to represent simple
3.They can draw the diagrams to represent simple
circuits.
circuits.
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ACTIVITY
ACTIVITY
− 1<br>
+ 1
−ACTIVITY 2<br>
+ACTIVITY 2
ACITIVITY 3
ACITIVITY 3
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The
The
− important effects of electricty,<br>
+ important effects of electricty,
Electric appliances,non
Electric appliances,non
− contact forces-charges<br>
+ contact forces-charges
And magnets
And magnets
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When
When
− current flows through the substances, it shows chemical <br>
+ current flows through the substances, it shows chemical
magnetic
magnetic
− effect and heating effect. <br>
+ effect and heating effect.
Magent attracts magnetic materials.
Magent attracts magnetic materials.
− Force of magnets is<br>
+ Force of magnets is
non- contact force .
non- contact force .
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1.The
1.The
students identify the different effects shown by electricity in
students identify the different effects shown by electricity in
− some situations<br>
+ some situations
2.The students recall the different effects of
2.The students recall the different effects of
− electricity <br>
+ electricity
3.The students give examples for magnetic
3.The students give examples for magnetic
− materials<br>
+ materials
4.The studetns can idntify the non contact forces
4.The studetns can idntify the non contact forces
such as magnetic force
such as magnetic force
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1.The
1.The
students perform activities show the heating effect of
students perform activities show the heating effect of
− electricity. <br>
+ electricity.
2.The students differentiate between magnetic and
2.The students differentiate between magnetic and
− nonmagnetic materials<br> In the given objects.<br>
+ nonmagnetic materials In the given objects.
3.The students
3.The students
can perform experiment to show the attractive propery of
can perform experiment to show the attractive propery of
− magnets<br>
+ magnets
4. The students show the existance of non contact
4. The students show the existance of non contact
forces
forces
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−ACTIVITY4<br>
+ACTIVITY4
−ACTIVITY5<br>
+ACTIVITY5
ACTIVITY
ACTIVITY
6
6
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−|
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'''CONCEPT
'''CONCEPT
−DEVELOPMENT'''
DEVELOPMENT'''
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Magnets
Magnets
− and their properties, magnetic field lines<br>
+ and their properties, magnetic field lines
Magnetic
Magnetic
− materials,some fields where magnets <br>
+ materials,some fields where magnets
are used,power and
are used,power and
− electric power,<br>
+ electric power,
sources of electricity,unit of electric energy
sources of electricity,unit of electric energy
−consumed
consumed
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1.The
1.The
− students recall the properties of the magnets.<br>
+ students recall the properties of the magnets.
2.The students
2.The students
− understand the applications of magents.<br>
+ understand the applications of magents.
3.They will be able to
3.They will be able to
− identify the strentgh of magnets at various palces around<br>
+ identify the strentgh of magnets at various palces around
− the magents<br>
+ the magents
4.They will be able to recall definitions of work
4.They will be able to recall definitions of work
− and electric energy consumed<br>
+ and electric energy consumed
5.They will be able to recall the
5.They will be able to recall the
− units of work and electric energy consumed<br>
+ units of work and electric energy consumed
6.They will recall
6.They will recall
the different sources of electricity
the different sources of electricity
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1.The
1.The
students can perform activities to find out the properties of
students can perform activities to find out the properties of
− magnets.<br>
+ magnets.
2. The students differentiates between magnets
2. The students differentiates between magnets
− between the magnets and<br> Non magnetic materials using the
+ between the magnets and Non magnetic materials using the
− properties of the magnets<br>
+ properties of the magnets
3. Can design simple devices which
3. Can design simple devices which
− work on the properties of the magnets<br>
+ work on the properties of the magnets
−|
|
−ACTIVITY7<br>
+ACTIVITY7
−ACTIVITY8<br>
+ACTIVITY8
ACTIVITY
ACTIVITY
− 9<br>
+ 9
−ACTIVITY10<br>
+ACTIVITY10
−|
|
Magnetic
Magnetic
− field lines and the property of magnetic<br>
+ field lines and the property of magnetic
field lines,relation
field lines,relation
− between electricity and magnetic<br>
+ between electricity and magnetic
Field. Oersted's
Field. Oersted's
− experiment,pattern of magentic <br>
+ experiment,pattern of magentic
Fields in various
Fields in various
− situations,elecric potential and <br>
+ situations,elecric potential and
Potential diference,
Potential diference,
− electric current necessity of <br>
+ electric current necessity of
electriomagnetic force in the
electriomagnetic force in the
flow of current.
flow of current.
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1.
1.
The students identify magnetic field lines around diffetn shapes
The students identify magnetic field lines around diffetn shapes
− of magents.<br>
+ of magents.
2. The students recall the properties of magnetic
2. The students recall the properties of magnetic
− lines of force<br>
+ lines of force
3. The students can identify the relation
3. The students can identify the relation
− between magentism and electricity<br>
+ between magentism and electricity
4. They can recall Ohm's
4. They can recall Ohm's
− law<br>
+ law
5. They can define potential,potential difference,electric
5. They can define potential,potential difference,electric
− current and emf.<br>
+ current and emf.
−|
|
1.
1.
− Calculate voltage, current and resistance using Ohm’s law.<br>
+ Calculate voltage, current and resistance using Ohm’s law.
2.
2.
Analyze circuit diagrams for series circuits and parallel
Analyze circuit diagrams for series circuits and parallel
− circuits.<br>
+ circuits.
3. Can calculate the electric energy consumed in
3. Can calculate the electric energy consumed in
− various situations<br>
+ various situations
4. Solve equations that relate electric
4. Solve equations that relate electric
− power to current, voltage and electrical<br> Energy.<br>
+ power to current, voltage and electrical Energy.
−|
|
−ACTIVITY11<br>
+ACTIVITY11
−ACTIVITY12<br>
+ACTIVITY12
ACTIVITY
ACTIVITY
− 13<br>
+ 13
−ACTIVITY14<br>
+ACTIVITY14
−|
|
−Ohm's<br>
+Ohm's
law,
law,
− concept of resistance and resistivity,<br>
+ concept of resistance and resistivity,
combination of
combination of
− resistances,electric energy<br>
+ resistances,electric energy
consumed,heat produced, steps to
consumed,heat produced, steps to
save electricity.
save electricity.
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The
The
flow in unit time is called electric current. In a conductor
flow in unit time is called electric current. In a conductor
− the<br>
+ the
flow also depends on the resistance of the wire. The
flow also depends on the resistance of the wire. The
− resistance of a <br>
+ resistance of a
Wire is made useful in many
Wire is made useful in many
− situations,specially to produce heat.<br>
+ situations,specially to produce heat.
As electric current is
As electric current is
the best form of energy, it should be saved.
the best form of energy, it should be saved.
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6.The
6.The
− students list the factors on which resistance depeds<br>
+ students list the factors on which resistance depeds
7.The
7.The
students will identify the heat produced when current flows
students will identify the heat produced when current flows
− through resistances<br>
+ through resistances
−8.They describe resistivity.<br>
+8.They describe resistivity.
9.They
9.They
students briefly expain the methods to save electric current
students briefly expain the methods to save electric current
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5.
5.
Describe devices and procedures for maintaining electrical
Describe devices and procedures for maintaining electrical
− safety.<br>
+ safety.
−6.They draw simple circuits .<br>
+6.They draw simple circuits .
7. The students
7. The students
− perform activity to prove Ohm's law.<br>
+ perform activity to prove Ohm's law.
8.They obtaining the
8.They obtaining the
skill of calculating the problems on Ohm's law
skill of calculating the problems on Ohm's law
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−|
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Electromagnetic
Electromagnetic
− Induction,Faraday' laws,AC and DC,<br>
+ Induction,Faraday' laws,AC and DC,
fleming's rules,AC and DC
fleming's rules,AC and DC
− dynamo, Types of <br>
+ dynamo, Types of
Electromagnetic induction,Eddy currents and
Electromagnetic induction,Eddy currents and
Lenz' law.
Lenz' law.
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When
When
− magnetic field inked with the conductor changes an emf is<br>
+ magnetic field inked with the conductor changes an emf is
induced
induced
in thre conductor. The induced emf depends on rate of change
in thre conductor. The induced emf depends on rate of change
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1
1
.The students observe the experimental evidence for
.The students observe the experimental evidence for
− electromagnetic induction. <br>
+ electromagnetic induction.
2.They understand the
2.They understand the
circumstances under which changing magnetic fields lead to
circumstances under which changing magnetic fields lead to
−induced currents.<br>
+induced currents.
3.They understand how the movement of a
3.They understand how the movement of a
− conductor through a magnetic field leads<br>
+ conductor through a magnetic field leads
to an induced emf.
to an induced emf.
−4.They understand and use Lenz’s law for induced currents.
4.They understand and use Lenz’s law for induced currents.
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1.The
1.The
students can perform activities to prove Farady's experiment on
students can perform activities to prove Farady's experiment on
−electromagnetic induction
electromagnetic induction
|
|
−ACTIVITY15<br>
+ACTIVITY15
−ACTIVITY16<br>
+ACTIVITY16
ACTIVITY
ACTIVITY
− 17<br>
+ 17
−ACTIVITY18<br>
+ACTIVITY18
−ACTIVITY19<br>
+ACTIVITY19
−ACTIVITY20<br>
+ACTIVITY20
−ACTIVITY 21<br>
+ACTIVITY 21
−|
|
Induction,
Induction,
− solenoid, field lines in solenoid,motor and<br>
+ solenoid, field lines in solenoid,motor and
Its
Its
− applications.Domestic circuits,<br>
+ applications.Domestic circuits,
Steps to save electricity
Steps to save electricity
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The
The
− direction of emf is <br>
+ direction of emf is
perpendicular to magnetic field. The
perpendicular to magnetic field. The
advantages of AC in power generation; why we do not generate
advantages of AC in power generation; why we do not generate
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5.They
5.They
use Lenz’s law and Faraday’s law to determine the direction
use Lenz’s law and Faraday’s law to determine the direction
− and size of<br>
+ and size of
−Induced currents.<br>
+Induced currents.
6.They recall the laws of
6.They recall the laws of
− electromagnetic Induction, fleming's rules.<br>
+ electromagnetic Induction, fleming's rules.
7. The students
7. The students
− differentiate between AC And DC; a motor and a dynamo<br>
+ differentiate between AC And DC; a motor and a dynamo
9. The
9. The
− students will mention the use of dynamos and motors<br>
+ students will mention the use of dynamos and motors
10.The
10.The
students will be able to describe the methods to save
students will be able to describe the methods to save
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2.
2.
− The students can draw the diagrams of AC dynamo,DC dynamo,<br>
+ The students can draw the diagrams of AC dynamo,DC dynamo,
3.
3.
− They can represent AC and DC with graph.<br>
+ They can represent AC and DC with graph.
4.They can construct
4.They can construct
− simple Dynamo<br>
+ simple Dynamo
−5. They can construct simple motor<br>
+5. They can construct simple motor
6. They
6. They
− can explain the working of Dynamo and Motor<br>
+ can explain the working of Dynamo and Motor
7. They can
7. They can
perform activity to expain lenz's law
perform activity to expain lenz's law
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−# Electromagnetic induction, Faraday's laws, understand the functioning of a DC motor and AC dynamo
# Electromagnetic induction, Faraday's laws, understand the functioning of a DC motor and AC dynamo
[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_b641926.png]]<br>
+[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_b641926.png]]
−|-
|-
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−[[Image:Electron.jpg]]<br>
+[[Image:Electron.jpg]]
−|
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−[[Image:proton.jpg]][[Image:proton.jpg]]<br>
+[[Image:proton.jpg]][[Image:proton.jpg]]
[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_m2f27def.png]]<br>
+[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_m2f27def.png]]
−=== Speed and source of electrons in a circuit ===
=== Speed and source of electrons in a circuit ===
|
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−[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_m4b1bf843.jpg]]<br>
+[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_m4b1bf843.jpg]]
[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_1f7d7930.jpg]][[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_m3142907a.jpg]]<br>
+[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_1f7d7930.jpg]][[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_m3142907a.jpg]]
−[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_m57cad797.png]][[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_38133c13.png]]<br>
+[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_m57cad797.png]][[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_38133c13.png]]
−# [[http://www-istp.gsfc.nasa.gov/Education/Imagnet.html]]
# [[http://www-istp.gsfc.nasa.gov/Education/Imagnet.html]]
[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_m78bd27f.jpg]][[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_677bab2f.jpg]]<br>
+[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_m78bd27f.jpg]][[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_677bab2f.jpg]]
−[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_m5d4cf08f.jpg]]<br>
+[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_m5d4cf08f.jpg]]
−[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_2757b930.png]][[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_7ad1ee04.png]]<br>
+[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_2757b930.png]][[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_7ad1ee04.png]]
−<u>Principle</u>:
<u>Principle</u>:
−Moving electrons. magnetism<br>
+Moving electrons. magnetism
<u>Prοcedure:</u>
<u>Prοcedure:</u>
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<u>Principle</u>:
<u>Principle</u>:
−Moving electrons. Magnetism <br>
+Moving electrons. Magnetism
<u>Procedure:</u>
<u>Procedure:</u>
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−* M[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_45126618.png]]ove compass to various locations around the bar magnet. Explain what orientation the needle takes with respect to the bar magnet.
* M[[Image:Electromagnetism_%20Resource_Material_Subject_Teacher_Forum_September_2011_html_45126618.png]]ove compass to various locations around the bar magnet. Explain what orientation the needle takes with respect to the bar magnet.
* '''Make observations & draw conclusions.''' Using the same setup as you used in step 4 move the filed meter from place to place and observe how the field strength changes. Write a general rule for how changing the distance from the magnet affects the magnetic fields strength.
* '''Make observations & draw conclusions.''' Using the same setup as you used in step 4 move the filed meter from place to place and observe how the field strength changes. Write a general rule for how changing the distance from the magnet affects the magnetic fields strength.
* '''Make observations & draw conclusions.''' Use the same setup as you used in step 4 but change the source of current to AC. Your screen should look something like what you see to the right, Screen 3. Observe how the AC changes the compass and the magnetic field strength. Write down your observations regarding the change in the strength and direction of the magnetic field. Describe a way to get a DC supplied electromagnet to change the direction of the magnetic field, like the AC does.
* '''Make observations & draw conclusions.''' Use the same setup as you used in step 4 but change the source of current to AC. Your screen should look something like what you see to the right, Screen 3. Observe how the AC changes the compass and the magnetic field strength. Write down your observations regarding the change in the strength and direction of the magnetic field. Describe a way to get a DC supplied electromagnet to change the direction of the magnetic field, like the AC does.
−
