Electromagnetics - Two long wires carry equal, but opposite currents

AI Thread Summary
Two long wires carrying equal but opposite currents of 25 A create a magnetic field at point P, located 0.05 m between them. The proposed formula for calculating the magnetic field magnitude is B = (4pi * 10^-7)(25) / (2)(pi)(0.05). To solve the problem, one must consider the expression for the magnetic field from a long straight wire and determine the direction of the magnetic fields from both wires at point P. The fields should be added vectorially, but the problem can be simplified through inspection, as the magnitudes and directions can be intuitively understood without extensive calculations. Understanding the setup allows for a clearer grasp of the magnetic field's behavior in this scenario.
Drevin
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Another Electromagnetics question...

Two long wires carry equal, but oppositely directed, 25 A currents. What is the magnitude of magnetic field due to these currents at point P? The wires are 0.1 m apart and point P is 0.05m in between the wires.

Would the following be the correct way to solve it?

B = (4pi * 10^-7)(25) / (2)(pi)(0.05)

(Phys. 12)
 
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Drevin said:
Another Electromagnetics question...

Two long wires carry equal, but oppositely directed, 25 A currents. What is the magnitude of magnetic field due to these currents at point P? The wires are 0.1 m apart and point P is 0.05m in between the wires.

Would the following be the correct way to solve it?

B = (4pi * 10^-7)(25) / (2)(pi)(0.05)

(Phys. 12)

1. Do you know the expression for magnetic field set up by a long straight wire (of course you do).

2. At point P can you determine the directions of the two fields (due to the two wires)?

3. Determine the fields and add them vectorially :smile:
 
HINT: The question is easier than it first seems and can be answered by inspection; no calculations are nesscary, but they could be used to obtain the same answer. Think bout what determines the magnitude of the magnetic field. Think about what determines the direction of the magnetic field.

:wink:
~H
 
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