List of Topics

SfC Home > Physics > Magnetism >


Feedback Comments on Magnetism

by Ron Kurtus

A total of 677 comments and questions have been sent in. They are listed according to date.

You can read them to further your understanding of the subject.

List of most recent 10 letters




Electromagnetism Relationship between magnetic force and electricity Nigeria
Magnetism Magnetic alignment Ghana
Basics of Magnetism Reducing permanent magnetism New Zealand
Magnetic Materials Wands free books on EMF Ethiopia
Moving Charges Create Magnetic Field How is magnetic field created? India
General Device using small disc magnet Canada
Solenoids Solenoid and electromagnet India
Basics of Magnetism Questions on electromagetism India
Electromagnetic Devices How do electromagnets work in railway signals? India
Electromagnets Placing electromagnet inside another electromagnet USA

Next 10

Relationship between magnetic force and electricity

Topic: Electromagnetism


October 23, 2018

my question is, what is the relationship between magnetic force and electricity?

Abdulrahman - Nigeria



See Moving Electrical Charges Create Magnetic Field. It shows that when electrical charges move, they create a magnetic force field. Likewise, a magnetic force can create electricity. See Basics of Electromagnetism.

Back to top

Magnetic alignment

Topic: Magnetism


October 8, 2018

what is in the iron that makes magnetic substance attracted by it

obed - Ghana



It is the alignment of the electrons. See: Factors Determining Magnetic Properties.

Back to top

Reducing permanent magnetism

Topic: Basics of Magnetism


October 6, 2018

If you have a weak permanent magnet and wind a multi turn coil around it and then pass an electrical current through the coil, can you negate the magnet strength of the magnet?
Will a specific current be required to reduce the magnet strength to exactly zero?

Charlie - New Zealand



You can demagnetize a permanent magnet by hitting it with a hammer or heating it to a sufficient temperature. Both cases disrupt the alignment of the atoms.

The problem with using a coil is that the atoms can be realigned into a different direction, thus still maintaining the magnetism. The only way to reduce the strength of the magnet is to get some or all of the atoms in random orientation.

Back to top

Wands free books on EMF

Topic: Magnetic Materials


May 30, 2018

Hello I am bereket, age 20 and I'm from Ethiopia. I want to ask you how I can get free online books on EMF.

Bereket - Ethiopia



There are some free downloads on EMF from Free Books - EMF.

I'm not sure how extensive they are, but they might give you what you want.

Best wishes for success in your studies.

Back to top

How is magnetic field created?

Topic: Moving Charges Create Magnetic Field


November 7, 2017

how megnetic field created around electric current

ravi - India



Electrical charges have an electric field around them. When the charges move a magnetic field is created perpendicular to that movement. An electric current consists of moving electrical charges.

Back to top

Device using small disc magnet

Topic: General


September 6, 2017

Good morning Ron. My son and I are developing a low tech medical device that relies on the attraction between a small disc magnet 20 mm x 2 mm and a similarly sized flat washer. We're having a problem with the amount of attraction between the two and need to increase it and are thinking about increasing the size of the magnet or the washer but are constrained in doing this due to physical dimensions. Is there anything readily available such as a flat washer or disc with a higher than normal iron content that would cause the magnet to be more strongly attracted to it? Many thanks!

Niall - Canada



You might try a Neodymium disc magnet. They are small, strong and inexpensive and can be bouht through or other outlets.

I hope that helps. Best wishes for success with your device.

Back to top

Solenoid and electromagnet

Topic: Solenoids


June 13, 2017

Why solenoid is used for making electromagnet

Nishant - India



A solenoid is an electromagnet without the iron core in it. The solenoid can be used to pull a core inside it.

Back to top

Questions on electromagetism

Topic: Basics of Magnetism


February 17, 2017

DC Electromagnet.
1. Ratio of Core area & Poles face area.
3. If three sides of magnet is covered with non magnetic material will there be more force on pole faces.
4. Construction & operation details of

tks. rgds, Vish

Viswanatan - India



See our lessons on Electromagnetism. They should help answer some of your questions.

Back to top

How do electromagnets work in railway signals?

Topic: Electromagnetic Devices


February 14, 2017

How electromagnet works in railway signals?

Harsh - India



Railway signals can be flashing lights or a moving barrier.

An electromagnet could be used as a solenoid to turn on or turn off the railway signals.

The barrier is usually moved by an electric motor.

Back to top

Placing electromagnet inside another electromagnet

Topic: Electromagnets


February 5, 2017

I have a new found curiosity for electromagnets. I'm not a scientist or even a student... just curious. What would happen if your electromagnet core contained another electromagnet?

Ron - USA



If the core is movable, you would have a solenoid of sorts. (See Solenoids are Electromagnetic Devices).

Instead of having a movable iron core or magnet core, you would place an electromagnet there. This would allow movement of the core to be finely tuned. However, I don't think I've even seen such a configuration.

Back to top

Next 10


Hopefully, this reader feedback has helped provide information about Magnetism issues.

Always do your best

Resources and references

Ron Kurtus' Credentials


Magnetism Resources


Top-rated books on Magnetism

Questions and comments

Do you have any questions, comments, or opinions on this subject? If so, send an email with your feedback. I will try to get back to you as soon as possible.

Feel free to establish a link from your website to pages in this site.

Where are you now?

School for Champions

Magnetism topics

Feedback on Magnetism

Magnetism topics



Also see

Let's make the world a better place

Be the best that you can be.

Use your knowledge and skills to help others succeed.

Don't be wasteful; protect our environment.

You CAN influence the world.

Live Your Life as a Champion:

Take care of your health

Seek knowledge and gain skills

Do excellent work

Be valuable to others

Have utmost character

Be a Champion!

The School for Champions helps you become the type of person who can be called a Champion.