Factors that affect the strength of electromagnets are the nature of the core material, strength of the current passing through the core, the number of turns of wire on the core and the shape and size of the core.

The do-it-yourself assembly of an electromagnet is a common science experiment that demonstrates the marriage of electricity and magnetism as a unified force. You can use any type of battery for this project, including a 9-volt (9V) battery.

If you add the turns to the middle, then you make the field stronger there. Adding more turns in the coil can also increase the total resistance of the wire. If you’re powering the magnet with a constant voltage source (like a battery), the current will be inversely proportional to the resistance in the wire.

Steel is more difficult to magnetise and is not easily demagnetised. An iron core makes a temporary electromagnet. It loses its magnetism as soon as the switch is opened and the current is switched off. A steel core makes a more permanent magnet.

Electromagnets are very widely used in electric and electromechanical devices, including:

• Motors and generators.
• Transformers.
• Relays.
• Electric bells and buzzers.
• Loudspeakers and headphones.
• Actuators such as valves.
• Magnetic recording and data storage equipment: tape recorders, VCRs, hard disks.
• MRI machines.

It is possible to make an electromagnet repel a permanent magnet. To accomplish this the electromagnet’s current needs to induce a magnetic field “He” in the core which is stronger then the opposite field Hm that the magnet is inducing on that same core.

Electromagnets can either attract or repel each other, depending on which direction they are pointing. You can make electromagnets that repel with some small batteries, wire and iron nails.

Push-Pull Operation: While physically maintaining both electromagnet and cap on same axis, the cap pulls (attracts) the electromagnet when DC power is off. The electromagnet pushes (repels) the cap when DC power is on. When DC power is momentarily on, the electromagnet exerts a repulsive force on the cap.

Usually, a ferromagnetic material like steel is wrapped by an electromagnet to enhance its magnetic field….

The switch is built with 3 equal magnets and you will need some iron bars. It’s obviously not possible to turn off the magnetic field of a permanent magnet. They must be of the same size and strength for the magnetic fields to eventually collapse.

Problem is that seller states that it should not be used for more than 5-10 minutes at a time (without severe reduced lifespan).

copper wire

A circular coil shape is the optimum use of wire to obtain the largest magnetic flux. Any deviation from a circle will use more wire for a given coil area and the extra coil resistance can reduce the peak current into the coil or, necessitate more power having to be delivered to the coil to obtain the same current.

neodymium

A simple way to magnetize water is to keep two liter jugs of water on the two poles of encased disc magnets of about 3000 gausses, normally for twelve to twenty-four hours.

Water is capable of being magnetized. Like oxygen, it’s paramagnetic, meaning that it holds a magnetic charge. More pseudoscientific garbage. [link] Water is not paramagnetic and oxygen is not ferromagnetic.

Proper use of magnetic field (MF) can change the properties of water. The evaporation amount of water increase 38.98% after magnetization. The specific heat and boiling point of water decrease after magnetization.

Rub the metal with the magnet in the opposite direction that you used to magnetize it. Continue rubbing until the metal no longer attracts other metal. Wait out the magnetization, if desired. It is not necessary to demagnetize metal if time is not an issue because metal loses it magnetism over time.

Temporary magnets are made from soft metals, and only retain their magnetism while near a permanent magnetic field or electronic current. Common temporary magnets include nails and paperclips, which can be picked up or moved by a strong magnet.

The difference between a permanent magnet and a temporary magnet is in their atomic structures. Permanent magnets have their atoms aligned all the time. Temporary magnets have their atoms aligned only while under the influence of a strong external magnetic field.

Temporary magnets are those that simply act like permanent magnets when they are within a strong magnetic field. Unlike permanent magnets however, they loose their magnetism when the field disappears. Paperclips, iron nails and other similar items are examples of temporary magnets.

Characteristics, properties & types of magnets….

Uses of temporary magnets would be paper clips and nails and other soft iron items as examples used for temporary magnets. Temporary magnets are commonly used in electric motors and telephones and speakers. Temporary magnets are also used to make temporary electromagnets.

The main point to take away from the definition of a temporary magnet is that it can’t retain its magnetism without assistance from another source….Permanent Magnets Vs. Temporary Magnets.