posted by sophie .
The polarity of an electromagnetic can be determined using the second right-hand rule.
Is it false?
Current passing through a conductor is increased from 10 A to 15 A. This decreases the strength of the magnetic field produced by the conductor.
is it true?
If you know how the electromagnet is wound and what direction the current is flowing through the magnet coil, you can get the direction of the magnetic field through the magnet by a right hand rule. I do not know what you call first or second.
The B field around the conductor is proportional to the current through it, so true.