Explanation:

To understand why ebonite cannot be used to make a magnet, let's first discuss what a magnet is and how it is formed.

What is a magnet?
A magnet is an object that produces a magnetic field around it. It has the ability to attract certain materials, such as iron, nickel, and cobalt. Magnets have two poles - a north pole and a south pole. Like poles repel each other, while opposite poles attract each other.

How are magnets formed?
Magnets can be formed through a process called magnetization. This process involves aligning the magnetic domains within a material in a specific direction. Magnetic domains are regions within a material where the magnetic atoms are grouped together and aligned in the same direction.

Materials that can be used to make a magnet:
In order to make a magnet, the material should be able to be magnetized. Some common materials that can be used to make magnets include:

1. Cobalt: Cobalt is a ferromagnetic material, which means it can be easily magnetized. It has a high magnetic permeability and can retain a strong magnetic field.

2. Iron: Iron is also a ferromagnetic material and is widely used in making magnets. It has a high magnetic permeability and can be magnetized easily.

3. Steel: Steel is an alloy of iron and other elements, such as carbon. It can be magnetized and is commonly used to make permanent magnets.

Why ebonite cannot be used to make a magnet:
Ebonite, also known as hard rubber, is a non-magnetic material. It does not have any magnetic properties and cannot be magnetized. Ebonite is made from vulcanized rubber, which is a polymer material. Polymers do not have magnetic domains that can be aligned to create a magnetic field. Therefore, ebonite cannot be used to make a magnet.

Conclusion:
In summary, ebonite cannot be used to make a magnet because it is a non-magnetic material. Only materials with magnetic properties, such as cobalt, iron, and steel, can be magnetized and used to make magnets.