Confused About Right Hand Rule: Understanding Magnetic Fields

In summary: You use it just like you (and the link I gave) describe. Try to picture the magnetic field lines as circles in three dimensions surrounding the wire. The field always points tangent to the circle in the direction given by the RHR. Then you have to determine what direction the field points where it touches the page.
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lha08
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Homework Statement


I'm so confused about how to use the right hand rule..there are so many different sources telling me different things...like i need to use the RHR to like find the direction of the magnetic field using the current (and nothing else)..like i followed my book, and they said to use my thumb to point towards the current and wrap my fingers around the wire as if i was holding it in my hand, and the direction of the wrapped fingers would give the direction of the magnetic field, but everytime i do it for a question or something, even though the current is in the same direction, some questions tell me that the Magnetic field is in 2 complete different directions...like one will say the the M. field is out of the paper and the other into the paper even though the current is flowing in the exact some direction...help!


Homework Equations





The Attempt at a Solution

 
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  • #3
Doc Al said:
Realize that the magnetic field forms concentric circles around the current-carrying wire. So, if current is moving from right to left (in the plane of the paper) then the magnetic field points into the page above wire and out of the page below it. See: http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/magcur.html#c1"

But like when we solve problems, is there a specific way to use the RHR that will tell us if it's coming or going in the page at a specific current even though it moves in a circle?
Like when you said that when the current is moving from right to left, what do you mean by 'the magnetic field points into the page above wire and out of the page below it'...?
 
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  • #4
lha08 said:
But like when we solve problems, is there a specific way to use the RHR that will tell us if it's coming or going in the page at a specific current even though it moves in a circle?
You use it just like you (and the link I gave) describe. Try to picture the magnetic field lines as circles in three dimensions surrounding the wire. The field always points tangent to the circle in the direction given by the RHR. Then you have to determine what direction the field points where it touches the page.
Like when you said that when the current is moving from right to left, what do you mean by 'the magnetic field points into the page above wire and out of the page below it'...?
In that example, the wire is in the plane of the paper, so the magnetic field lines are circles perpendicular to the page. You must imagine how those field lines intersect the page. Where they touch the page above the wire, they are pointing directly into the page.

Take a look at Fig 28.6 on this page (down toward the bottom); it might help you visualize what's going on: http://www.physics.sjsu.edu/becker/physics51/mag_field.htm"
 
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1. What is the right hand rule?

The right hand rule is a method used to determine the direction of a magnetic field in relation to the direction of current flow. It is based on the fact that a magnetic field is created by current flowing through a wire.

2. Why is the right hand rule important?

The right hand rule is important because it allows us to predict the direction of a magnetic field, which is essential in many applications such as electromagnets, motors, and generators. It also helps us understand the relationship between current and magnetic fields.

3. How do you use the right hand rule?

To use the right hand rule, point your thumb in the direction of current flow, and then curl your fingers in the direction of the magnetic field. Your fingers will point in the direction of the magnetic field lines. Alternatively, you can point your fingers in the direction of current flow and your thumb will point in the direction of the magnetic field.

4. Can the right hand rule be used for all types of current?

No, the right hand rule is specifically used for direct current (DC) and single-phase alternating current (AC). For three-phase AC, the left hand rule is used.

5. Are there any variations of the right hand rule?

Yes, there are variations of the right hand rule depending on the specific application. For example, in motors and generators, the right hand rule can be used to determine the direction of force acting on a wire in a magnetic field. In electromagnets, the right hand grip rule is used to determine the direction of current flow in relation to the direction of the magnetic field.

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