Magnetic field in a infinitley long wire

In summary, a magnetic field in an infinitely long wire is a region in space created by the flow of electric current through the wire. Its direction can be determined using the right-hand rule and its strength is directly proportional to the current and decreases with distance. It can affect nearby objects and cannot be turned off, but its strength can be altered by changing the current.
  • #1
hitman0097
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Homework Statement


An infinitely long wire lies along the z axis and carries a current of 12 A in the positive z direction. A second infinitely long wire is parallel to the z axis at x = 8.2 cm.

a.)Find the current in the second wire if the magnetic field at x = 1.6 cm is zero.
b.)What is the magnetic field at x = 5 cm?


Homework Equations


F=I(LxB)


The Attempt at a Solution


I am lost with this one.
 
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  • #2
What is the relevant equation for the field due to current carrying infinite long wire?
 
  • #3


I would approach this problem by first understanding the concept of a magnetic field and how it is affected by a current-carrying wire. I would also need to know the formula for calculating the magnetic field in this scenario, which is given by the equation F=I(LxB), where F is the force, I is the current, L is the length of the wire, and B is the magnetic field.

For part a), I would start by setting up the problem and identifying the known variables. We know that the first wire has a current of 12 A and is located along the z axis. The second wire is parallel to the z axis at x = 8.2 cm. We are also given that the magnetic field at x = 1.6 cm is zero. From this information, we can use the formula F=I(LxB) to solve for the unknown current in the second wire.

F=I(LxB)
0=I(8.2 cm x B)
0=8.2 cm x B
B=0 cm/A

Since the magnetic field at x = 1.6 cm is zero, this means that the force (F) must also be zero. Therefore, the current in the second wire must also be zero in order for the magnetic field to be zero. This makes sense, as the two wires are parallel and there would be no force between them if there is no current in the second wire.

For part b), I would use the same formula F=I(LxB) to calculate the magnetic field at x = 5 cm. We know that the first wire has a current of 12 A and is located along the z axis. The second wire is parallel to the z axis at x = 8.2 cm. We can use the formula to solve for B.

F=I(LxB)
F=12 A(8.2 cm x B)
F=98.4 cm x B
B=F/98.4 cm

Since we don't have any information about the force (F) at x = 5 cm, we cannot calculate the exact value for the magnetic field. However, we can say that the magnetic field at x = 5 cm would be non-zero, as there is a current in the second wire and the two wires are not at the same location. The exact value for the magnetic field would depend on the force between the two wires, which
 

1. What is a magnetic field in an infinitely long wire?

A magnetic field in an infinitely long wire is a region in space around the wire where a magnetic force can be observed. It is created by the flow of electric current through the wire and is represented by magnetic field lines.

2. How is the direction of the magnetic field in an infinitely long wire determined?

The direction of the magnetic field in an infinitely long wire is determined by the right-hand rule. If you point your thumb in the direction of the current flow, the direction of the magnetic field will be in the direction your fingers curl around the wire.

3. What is the strength of the magnetic field in an infinitely long wire?

The strength of the magnetic field in an infinitely long wire is directly proportional to the current flowing through the wire. It also depends on the distance from the wire, with the strength decreasing as the distance increases.

4. How does the magnetic field in an infinitely long wire affect nearby objects?

The magnetic field in an infinitely long wire can exert a force on nearby objects that have a magnetic property, such as a compass needle. It can also induce an electric current in a nearby wire or conductor.

5. Can the magnetic field in an infinitely long wire be turned off?

No, the magnetic field in an infinitely long wire cannot be turned off as long as there is current flowing through the wire. However, the strength of the magnetic field can be altered by changing the amount of current flowing through the wire.

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