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| 184_notes:b_current [2021/06/16 18:53] – [Magnetic field from Many Charges] bartonmo | 184_notes:b_current [2021/07/07 15:29] (current) – schram45 |
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| {{youtube>4cIpX1HK7GM?large}} | {{youtube>4cIpX1HK7GM?large}} |
| ==== Magnetic field from Many Charges ==== | ===== Magnetic field from Many Charges ===== |
| [{{ 184_notes:Week9_4.png?400|Magnetic field on point P from many moving charges in a wire}}] | [{{ 184_notes:Week9_4.png?400|Magnetic field on point P from many moving charges in a wire}}] |
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| We will go into detail about how to put the pieces of this equation together in an example; however, it is important to realize that this equation doesn't really tell us anything new - we are still saying that **moving charges will create magnetic fields that point in a perpendicular direction and can be calculated for every point in space around the charge**. We also did not make very many assumptions in this derivation - only that //__we have many charges that are moving along the wire__//. Thus, this is a general equation that can be used for any current. | We will go into detail about how to put the pieces of this equation together in an example; however, it is important to realize that this equation doesn't really tell us anything new - we are still saying that **moving charges will create magnetic fields that point in a perpendicular direction and can be calculated for every point in space around the charge**. We also did not make very many assumptions in this derivation - only that //__we have many charges that are moving along the wire__//. Thus, this is a general equation that can be used for any current. |
| ==== Magnetic Field from a Very Long Wire ==== | ===== Magnetic Field from a Very Long Wire ===== |
| [{{ 184_notes:Week9_6.png?300|Problem set up to find the magnetic field at a point from a very long wire}}] | [{{ 184_notes:Week9_6.png?300|Problem set up to find the magnetic field at a point from a very long wire}}] |
| Let's look at a particular example of finding the magnetic field a distance $s$ away from a very long wire with some //__constant, steady state current__// I flowing from top to bottom. Since the wire is very long, we will //__assume for our purposes that it stretches from $+\infty$ to $-\infty$ in the y direction__//. If we start with the general magnetic field equation for a current, then we can start to fill in the pieces. | Let's look at a particular example of finding the magnetic field a distance $s$ away from a very long wire with some //__constant, steady state current__// I flowing from top to bottom. Since the wire is very long, we will //__assume for our purposes that it stretches from $+\infty$ to $-\infty$ in the y direction__//. If we start with the general magnetic field equation for a current, then we can start to fill in the pieces. |
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| ==== Examples ==== | ==== Examples ==== |
| [[:184_notes:examples:Week10_current_segment|Magnetic Field from a Current Segment]] | * [[:184_notes:examples:Week10_current_segment|Magnetic Field from a Current Segment]] |
| | * Video Example: Magnetic Field from a Current Segment |
| | * [[:184_notes:examples:Week10_current_ring|Challenge Example: Magnetic Field from a Ring of Current]] |
| | * Video Example: Magnetic Field from a Ring of Current |
| | {{youtube>nGrFo80MMzM?large}} |
| | {{youtube>HN0cHcbYcSo?large}} |
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