永磁体和电磁体

磁场和强度是永磁体和电磁体之间的主要区别。绕线线圈在电磁铁中产生磁场，而永久（条形）磁铁的磁场不能改变。永磁体的强度取决于其构造中使用的材料，但电磁体的强度取决于通过它的电流。陶瓷磁体、柔性磁体、钕铁硼磁体和钐钴磁体是永磁（条形）磁体的四种类型。每个都有自己的一组用途和种类。

让我们更详细地了解永磁体和电磁体之间的区别。

永磁体

These magnets have the ability to keep their magnetism and magnetic characteristics for a longer period of time. Permanent magnets are made up of strongly magnetic hard materials. The Bar Magnet is an excellent example of a permanent magnet. This magnet shows the behaviour of magnets in great detail. Permanent magnets are also known as Bar Magnets.

永磁体的类型

本节将讨论许多类型的永磁体。它们如下：

1. 陶瓷磁体：它们是最具成本效益的永磁体。我们将它们用于食品加工行业以及磁共振成像和其他领域。
2. 柔性磁铁：它们用于冰箱门封条。橡胶聚合物、塑料和磁粉都可以用来制造它们。
3. NdFeB（钕铁硼磁铁）：这些是稀土磁铁。很容易氧化。这是一种高价物质。它经常用于珠宝制作、装订和其他工艺。
4. 由钐钴 (SmCo) 制成的磁铁：这些也是稀土磁铁。它是耐高温和抗氧化的。它们有更强的磁场。它们可用于高端电机、涡轮机械和其他应用。

永磁体的应用

• 硬盘驱动器、电机、车辆、发电机、电视、电话、耳机、扬声器、换能器和传感器都需要永磁体。磁铁最常见的目的是吸引其他磁性物体，但它也用于电子设备中的各种任务。
• 大多数扬声器使用与线圈（实际上是电磁体）相互作用的永磁体。音频信号沿电缆传播并导致扬声器移动。扬声器通过移动空气产生声音。
• 橱柜或其他家具门上经常发现磁性挂钩或闭合件。通常，它们是使用夹在两块钢板之间的廉价陶瓷磁铁制造的，这些钢板吸引和接触门上的钢制“打击板”。

永磁体的缺点

• 永磁体的磁场只能在特定温度以下产生。因此，这些磁铁不适合在热设备应用中使用。
• 随着时间的推移，这些永磁体会劣化。结果，最大磁场强度降低。永磁体的磁极不能改变。

电磁铁

The device acts as a magnet when a battery is linked to a solenoid (a coil of wire coiled around a nail). The magnetic field created by the current flowing through the coil is responsible for this. The magnetism of the nail lasts as long as there is currently running through the coil; if there is no current, the magnetism of the nail is lost. When you wind a coil of wire around an iron core, you can make electromagnets.

电磁铁的种类

电磁铁分为电阻式、超导体或混合式。

1. 抗性电磁铁：这种磁铁使用铜线产生磁场。当铜线缠绕在一块铁上并且电流通过铜线时会产生磁场。电场越强，绞合的铜线就越多。
2. 混合电磁铁：它们是上述两种电磁铁的混合体，即电阻式电磁铁和超导电磁铁。
3. 超导磁体：它们由超导金属制成，对电流没有阻力。相同的方法用于制造超导磁体。在这些电磁铁中使用液氮或液氦降低铜线圈的温度。低温将铜原子与电流分离，从而产生高磁场。即使电源被切断，这些电磁铁仍继续函数。

电磁铁的应用

• 电磁铁是变压器中最常用的磁铁类型。当您向变压器供电时，线圈会产生不断变化的磁场。这导致产生电压。变压器通常用于电力系统中以管理交流电压。
• 您可以随时获得所需的电压。我们可以通过改变电流来实现这一点。电磁铁还可用于磁锁、继电器、磁悬浮、电铃和扬声器等。

电磁铁的缺点

• 大量的电磁体都需要铜连接。因此，它们不适合在紧凑的区域中使用。他们还需要大量的保养。电磁铁可能会因短路而损坏。
• 电磁铁需要一个恒流源。由于诸如欧姆加热、感应电压尖峰、磁芯损耗、线圈耦合等众多变量，这可能会在未来的某个时候影响磁体及其磁场。

永磁体和电磁体的区别

The difference between a permanent magnet and an electromagnet is as follows:

• Permanent magnets are permanently magnetized while electromagnets are temporarily magnetized.
• The former is made up of hard materials while the latter one is made up of soft materials.
• The magnetic field line’s intensity is fixed, i.e. it cannot be changed in permanent magnets while the magnetic field lines’ strength may be adjusted to suit our needs in electromagnets.
• The poles are fixed in the former one while the poles can be varied in the latter one.

永磁体和电磁体之间的相似之处

Both magnets have fictitious magnetic field lines. Magnets have north and south poles, and their behaviour is determined by the earth’s geographic north and south poles. The characteristics of magnetism are present in both magnets.

示例问题

问题一：为什么用软铁做电磁铁？

回答：

When the current flows, the soft iron inside the coil becomes a magnet, which strengthens the magnetic field. Because soft iron loses its magnetic as soon as the current stops flowing, it is a good choice.

问题二：厂家为什么要用钢来做永磁体？

回答：

Steel is an iron and carbon alloy. Steel is not magnetic in its native form, but it may be converted to become magnetic. When a nonmagnetic piece of steel is placed near a magnet, the atoms within it rearrange in such a way that a permanent magnet is formed. As the atoms align, a magnetic field is created that maintains its intensity. The atoms of an item must be appropriately aligned in order to produce a magnetic field. Because of the inherent arrangement of its atoms, steel is extremely useful for this purpose.

问题3：永磁体和电磁体有什么区别？

回答：

A permanent magnet is a material item that becomes magnetised and generates its own magnetic field. On the other hand, when an electric current is allowed to flow through a coil of wire, it functions as a magnet called electromagnet.

问题 4：与永磁体相比，电磁体有什么好处？

回答：

The major advantage of electromagnets is that they can control their magnetic pull intensity by turning the magnet on or off and changing the current. They also have a stronger draw than permanent magnets. According to some estimations, the biggest electromagnet is 20 times more powerful than the most powerful permanent magnet.

问题5：磁铁的用途是什么？

回答：

Electric generators utilise magnets to generate electricity, while electric motors use magnets to convert electrical energy into mechanical energy. Speakers, electric bells, maglev trains, TV and computer displays, cellphones, refrigerators, and other electronic devices utilise it.

问题6：电磁铁与永磁体相比有什么优势？

回答：

Permanent magnets are more expensive. Electromagnets are less expensive. This is due to the lower cost of the materials used in the electromagnet. An Electromagnet’s magnetic strength may be adjusted to suit your needs. In the event of a permanent magnet, this is not feasible.