PPT: Magnetostatics | Electromagnetic Fields Theory (EMFT) - Electrical Engineering (EE) PDF Download

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Magnetostatics Magnetostatics
nn Magnetostatics Magnetostatics is the branch of electromagnetics is the branch of electromagnetics
dealing with the effects of electric charges in steady dealing with the effects of electric charges in steady
motion (i.e, steady current or DC). motion (i.e, steady current or DC).
nn The fundamental law of The fundamental law of magnetostatics magnetostatics is is
Ampere’s law of force Ampere’s law of force..
nn Ampere’s law of force Ampere’s law of force is analogous to is analogous to Coulomb’s Coulomb’s
law law in electrostatics. in electrostatics.
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1
Magnetostatics Magnetostatics
nn Magnetostatics Magnetostatics is the branch of electromagnetics is the branch of electromagnetics
dealing with the effects of electric charges in steady dealing with the effects of electric charges in steady
motion (i.e, steady current or DC). motion (i.e, steady current or DC).
nn The fundamental law of The fundamental law of magnetostatics magnetostatics is is
Ampere’s law of force Ampere’s law of force..
nn Ampere’s law of force Ampere’s law of force is analogous to is analogous to Coulomb’s Coulomb’s
law law in electrostatics. in electrostatics.
2
Magnetostatics (Cont’d) Magnetostatics (Cont’d)
nn In magnetostatics, the magnetic field is In magnetostatics, the magnetic field is
produced by steady currents.  The produced by steady currents.  The
magnetostatic field does not allow for magnetostatic field does not allow for
nn inductive coupling between circuits inductive coupling between circuits
nn coupling between electric and magnetic fields coupling between electric and magnetic fields
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1
Magnetostatics Magnetostatics
nn Magnetostatics Magnetostatics is the branch of electromagnetics is the branch of electromagnetics
dealing with the effects of electric charges in steady dealing with the effects of electric charges in steady
motion (i.e, steady current or DC). motion (i.e, steady current or DC).
nn The fundamental law of The fundamental law of magnetostatics magnetostatics is is
Ampere’s law of force Ampere’s law of force..
nn Ampere’s law of force Ampere’s law of force is analogous to is analogous to Coulomb’s Coulomb’s
law law in electrostatics. in electrostatics.
2
Magnetostatics (Cont’d) Magnetostatics (Cont’d)
nn In magnetostatics, the magnetic field is In magnetostatics, the magnetic field is
produced by steady currents.  The produced by steady currents.  The
magnetostatic field does not allow for magnetostatic field does not allow for
nn inductive coupling between circuits inductive coupling between circuits
nn coupling between electric and magnetic fields coupling between electric and magnetic fields
3
Ampere’s Law of Force Ampere’s Law of Force
nn Ampere’s law of force Ampere’s law of force is the “law of action” is the “law of action”
between current carrying circuits. between current carrying circuits.
nn Ampere’s law of force Ampere’s law of force gives the magnetic force gives the magnetic force
between two between two current carrying circuits current carrying circuits in an in an
otherwise empty universe. otherwise empty universe.
nn Ampere’s law of force involves complete circuits Ampere’s law of force involves complete circuits
since current must flow in closed loops. since current must flow in closed loops.
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1
Magnetostatics Magnetostatics
nn Magnetostatics Magnetostatics is the branch of electromagnetics is the branch of electromagnetics
dealing with the effects of electric charges in steady dealing with the effects of electric charges in steady
motion (i.e, steady current or DC). motion (i.e, steady current or DC).
nn The fundamental law of The fundamental law of magnetostatics magnetostatics is is
Ampere’s law of force Ampere’s law of force..
nn Ampere’s law of force Ampere’s law of force is analogous to is analogous to Coulomb’s Coulomb’s
law law in electrostatics. in electrostatics.
2
Magnetostatics (Cont’d) Magnetostatics (Cont’d)
nn In magnetostatics, the magnetic field is In magnetostatics, the magnetic field is
produced by steady currents.  The produced by steady currents.  The
magnetostatic field does not allow for magnetostatic field does not allow for
nn inductive coupling between circuits inductive coupling between circuits
nn coupling between electric and magnetic fields coupling between electric and magnetic fields
3
Ampere’s Law of Force Ampere’s Law of Force
nn Ampere’s law of force Ampere’s law of force is the “law of action” is the “law of action”
between current carrying circuits. between current carrying circuits.
nn Ampere’s law of force Ampere’s law of force gives the magnetic force gives the magnetic force
between two between two current carrying circuits current carrying circuits in an in an
otherwise empty universe. otherwise empty universe.
nn Ampere’s law of force involves complete circuits Ampere’s law of force involves complete circuits
since current must flow in closed loops. since current must flow in closed loops.
4
Ampere’s Law of Force (Cont’d) Ampere’s Law of Force (Cont’d)
nn Experimental facts: Experimental facts:
nn Two parallel wires Two parallel wires
carrying current in the carrying current in the
same direction attract. same direction attract.
nn Two parallel wires Two parallel wires
carrying current in the carrying current in the
opposite directions opposite directions
repel. repel.
´ ´
I
1
I
2
F
12
F
21
´ ·
I
1
I
2
F
12 F
21
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1
Magnetostatics Magnetostatics
nn Magnetostatics Magnetostatics is the branch of electromagnetics is the branch of electromagnetics
dealing with the effects of electric charges in steady dealing with the effects of electric charges in steady
motion (i.e, steady current or DC). motion (i.e, steady current or DC).
nn The fundamental law of The fundamental law of magnetostatics magnetostatics is is
Ampere’s law of force Ampere’s law of force..
nn Ampere’s law of force Ampere’s law of force is analogous to is analogous to Coulomb’s Coulomb’s
law law in electrostatics. in electrostatics.
2
Magnetostatics (Cont’d) Magnetostatics (Cont’d)
nn In magnetostatics, the magnetic field is In magnetostatics, the magnetic field is
produced by steady currents.  The produced by steady currents.  The
magnetostatic field does not allow for magnetostatic field does not allow for
nn inductive coupling between circuits inductive coupling between circuits
nn coupling between electric and magnetic fields coupling between electric and magnetic fields
3
Ampere’s Law of Force Ampere’s Law of Force
nn Ampere’s law of force Ampere’s law of force is the “law of action” is the “law of action”
between current carrying circuits. between current carrying circuits.
nn Ampere’s law of force Ampere’s law of force gives the magnetic force gives the magnetic force
between two between two current carrying circuits current carrying circuits in an in an
otherwise empty universe. otherwise empty universe.
nn Ampere’s law of force involves complete circuits Ampere’s law of force involves complete circuits
since current must flow in closed loops. since current must flow in closed loops.
4
Ampere’s Law of Force (Cont’d) Ampere’s Law of Force (Cont’d)
nn Experimental facts: Experimental facts:
nn Two parallel wires Two parallel wires
carrying current in the carrying current in the
same direction attract. same direction attract.
nn Two parallel wires Two parallel wires
carrying current in the carrying current in the
opposite directions opposite directions
repel. repel.
´ ´
I
1
I
2
F
12
F
21
´ ·
I
1
I
2
F
12 F
21
5
Ampere’s Law of Force (Cont’d) Ampere’s Law of Force (Cont’d)
nn Experimental facts: Experimental facts:
nn A short current A short current- -
carrying wire oriented carrying wire oriented
perpendicular to a perpendicular to a
long current long current- -carrying carrying
wire experiences no wire experiences no
force. force.
´
I
1
F
12
= 0
I
2