Magnets are made of materials that attract objects made of certain substances like iron, cobalt, and nickel. The substances that are attracted by the magnet are called magnetic substances. For example, iron, steel, nickel and cobalt All types of materials and substances posses some kind of magnetic properties., but normally ferromagnetic materials are called magnetic materials. The materials can be classified into following categories based on the magnetic properties shown by them: The substances that are not attracted by the magnet are called non-magnetic substances. For example, wood, stone, leather, plastic,aluminium and copper.
These materials are barely magnetized when placed in a magnetic field. Magnetic dipoles in these substances tend to align in opposition to the applied field. In effect, they produce an internal magnetic field that opposes the applied field and the substance tends to repel the external field around it.
This opposing field disappears as soon as the external field is removed.
Ex: Gold, water, mercury and even animals!
In these materials the magnetic dipoles in the Magnetic Materials tend to align along the applied magnetic field and thus reinforcing the applied magnetic field. Such substances are attracted by a magnet if it applies a sufficiently strong field. It must be noted that such materials are still feeble magnetized and the magnetization disappears as soon as the external field is removed. Ex: Liquid oxygen, sodium, platinum, salts of iron and nickel.
We are most familiar with these materials as they exhibit the strongest magnetic behaviour. Magnetic dipoles in these materials are arranged into domains where the arrangements of individual magnetic dipoles are essentially perfect that can produce strong magnetic fields. Normally, these domains are usually randomly arranged and thus the magnetic field of each domain is cancelled by another and the entire material does not show any magnetic behaviour.
However when an external field is applied, the domains reorient themselves to reinforce the external field and produce a strong internal magnetic field that is along the external field. Upon, removal of the external field, most of the domains stay put and continues to be aligned in the direction of the (erstwhile) magnetic field. Thus, the magnetic field of the Magnetic Materials persists even when the external field disappears. This property is used to produce permanent magnets that we use every day. Iron, cobalt, nickel, neodymium and their alloys are usually highly ferromagnetic and are used to make permanent magnets.
A magnet attracts ferromagnetic materials like ______________. | |||
Right Option : D | |||
View Explanation |
Magnetite is a _______________________ | |||
Right Option : A | |||
View Explanation |
Which of the following are correct : (a) The substances that are attracted by the magnet are called magnetic substances. (b) The substances that are not attracted by the magnet are called magnetic substances. (c) Diamagnetic Materials are barely magnetized when placed in a magnetic field. | |||
Right Option : C | |||
View Explanation |
My experience was very good with Abhyas academy. I am studying here from 6th class and I am satisfied by its results in my life. I improved a lot here ahead of school syllabus.
A marvelous experience with Abhyas. I am glad to share that my ward has achieved more than enough at the Ambala ABHYAS centre. Years have passed on and more and more he has gained. May the centre flourish and develop day by day by the grace of God.
About Abhyas metholodology the teachers are very nice and hardworking toward students.The Centre Head Mrs Anu Sethi is also a brilliant teacher.Abhyas has taught me how to overcome problems and has always taken my doubts and suppoeted me.
One of the best institutes to develope a child interest in studies.Provides SST and English knowledge also unlike other institutes. Teachers are co operative and friendly online tests andPPT develope practical knowledge also.
Abhyas is a complete education Institute. Here extreme care is taken by teacher with the help of regular exam. Extra classes also conducted by the institute, if the student is weak.
I have spent a wonderful time in Abhyas academy. It has made my reasoning more apt, English more stronger and Maths an interesting subject for me. It has given me a habbit of self studying
It was a good experience with Abhyas Academy. I even faced problems in starting but slowly and steadily overcomed. Especially reasoning classes helped me a lot.
It was good as the experience because as we had come here we had been improved in a such envirnment created here.Extra is taught which is beneficial for future.
It has a great methodology. Students here can get analysis to their test quickly.We can learn easily through PPTs and the testing methods are good. We know that where we have to practice
Abhyas Methodology is very good. It is based on according to student and each child manages accordingly to its properly. Methodology has improved the abilities of students to shine them in future.