Electromagnets and Factors Affecting Their Strengths
The electromagnets are fundamental and useful devices as they are producing the controllable amount of magnetic force from the electric current. The strong magnets are cool and they have many turns of wire in the coil and are using larger amounts of current.
Description of Factors
Number of Coils
Usually, an electromagnet is the coil of insulated wire that is wound around an iron core. When there is running of electric current through it then it is magnetized and when the passing of current is stopped, the magnetism is lost. For making the electromagnets stronger, one can wind the coil more turns of wire. Then the number of turns is multiplied by the current in the amperes and it gives the ampere-turns that are the most important factor for the determination of the strength of the magnet. Moving of electric current around the loops of the coil causes the generation of the magnetic field that is similar to a bar magnet. By changing the number of loops in the coil, the strength of an electromagnet can be changed. By the addition of more loops, the filed becomes stronger. By the removal of loops, the strength of the magnetic field is reduced.
Current
Generally, the strength of the magnet is increased with the passage of greater electric current. At a certain point, the magnet will be saturated, and it will reach its maximum strength. By changing the amount of current, that is flowing through the electromagnet the strength can be changed. By lowering the voltage of the battery, the amount of current is reduced, and the strength of the field is also weakening. However, some complication is also associated in this fact as magnet wire gets hotter and it will damage the delicate insulation.
Core
The electromagnet will be stronger if the wire turns are winding around the metalcore. Typically, the best metals are iron-bearing or ferrous. The metal inside the coil is responsible for the magnification of filed that is created by it. By changing the core of metal, by different metals, the strengths of electromagnets can be made weaker or stronger. For the very strong fields, iron cores are used. Steel cores are known to make the weaker fields. The field can also be weakened by sliding the core partially out of the coil.
Temperature
The current-carrying abilities of the wire are improved with the low temperatures. Superconductors are used for making of strongest magnets. For this purpose, they are cooled with helium or liquified nitrogen.