The discussion revolves around the behavior of magnetic fields generated by two parallel wires carrying current in the same direction, and the implications for a neutral point where the resultant magnetic flux density is zero. Participants explore the direction of the current relative to the magnetic field and the movement of the neutral point as the current changes.
Some participants have provided hints and guidance regarding the relationship between the current direction and the resultant magnetic field. There is ongoing exploration of how increasing the current affects the neutral point's position, with various interpretations being discussed.
Participants note that the problem involves understanding the magnetic field behavior in relation to the distance from the wires and the current's effect on the field strength. There is also mention of the need to consider the uniform magnetic field present in the scenario.
But you said that B doesn't equal to zero, and now you say that the combined field from the wires cancels the uniform field.Doc Al said:When the current is increased, you need to also increase r if you want to keep the B constant.
But we have two wires to worry about. We're trying to find the point where the combined field from the wires cancels the uniform field. It used to be point P, but then they went and increased the current on us.
Closer to R?Doc Al said:Good! So which direction will the new 'neutral point' be?
The B from the two wires doesn't equal zero.moenste said:But you said that B doesn't equal to zero
That's right.moenste said:and now you say that the combined field from the wires cancels the uniform field.
Just the opposite. The field from the wires is proportional to I * (1/rQ - 1/rR). Since I is increasing, and we want B to remain the same, we need (1/rQ - 1/rR) to decrease.moenste said:Closer to R?
1 / 0.8 - 1 / 0.2 = - 3.75Doc Al said:Just the opposite. The field from the wires is proportional to I * (1/rQ - 1/rR). Since I is increasing, and we want B to remain the same, we need (1/rQ - 1/rR) to decrease.
That's true, but we want that factor to decrease, not increase.moenste said:If we want it to increase, we need to increase the distance from Q. Therefore P goes closer tto R.
Thank you, I think somehow I got it.Doc Al said:That's true, but we want that factor to decrease, not increase.