The Principle Of Making The Electromagnetic Iron

- Apr 10, 2018 -

1. A magnetic field formed by a circular coil leading to an electric current

(1) The direction of the magnetic field at the center of the coil can be regarded as a straight line on a small section of the coil, which is determined by the right-hand rule of Ampere.

(2) The magnetic field generated by each small segment of the current flowing through the circular coil is directed in the same direction within the coil. Therefore, the magnetic field in the coil is stronger than the magnetic field generated by the straight wire current.

(3) When a round wire is fed with a current, the magnetic field outside the coil is inconsistent with each other because of the direction of the magnetic field generated by each small segment of the current. Therefore, the resulting composite magnetic field is weaker than the magnetic field inside the coil.

(4) The larger the current of the circular coil and the smaller the radius, the greater the magnetic field strength at the center of the coil.

(5) The magnetic lines of the circular coil and the disk-shaped thin magnet are similar in shape.

2. Spiral coil current magnetic field

(1) A long spiral wound with a long wire is equivalent to a series of many circular coils. The magnetic field created by each circular wire in the center is in the same direction, which can enhance the effect. The magnetic field at the center is stronger than the single circle coil.

(2) The magnetic lines of force in the coil form the same straight line, and the magnetic lines of the coil gradually curve outwards at about both ends of the coil.

(3) The magnetic line characteristics of the spiral coil are similar to those of the bar magnet, and the magnetic lines in the coil are just opposite to the direction of the coil.

(4) The strength of the magnetic field within the coil is proportional to the current on the coil and the number of turns of the coil per unit length.

3. Spiral Coil Currents The right-hand spiral principle in the direction of the magnetic field (Ampere Theorem): Hold the coil with your right hand, and the four fingers point in the current direction. The direction in which the thumb points is the direction of the magnetic field lines in the coil.


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