Today trying to explain some magnetic stuff, just came across with a simple (at least seems) question.
My question is brief: does the direction of the magnetic field inside a solenoid depends on the direction which it is turned?
In other words -I hope you see the same as me-, I asking about if (1) is equal to (2):
(1) + -///////- –
(2) + -\\\\\\\- –
Best Answer
The direction of the magnetic field will correlate to the handedness of the current going through the coil. Basically it doesn't matter how the solenoid is constructed, what matters is the orientation of the current going through it. If you look along the length of the solenoid (through the coil), whether the current is moving clockwise or not, determines which magnetic pole will be closer to you.
The image below (from wiki) best explains the principle - as you can see, the magnetic field spirals around the current in a particular direction, and by causing the current to run past itself it stacks the magnetic field.
If you imagine that the current inside the solenoid is a rotating cylinder, the direction of that rotation determines the orientation of the magnetic field.