c) Electromagnets are only magnetized when a current flows through a wire wrapped around the core.
this is the answer
2. Electromagnets are much stronger than regular magnets
3. Electromagnets use coils while regular magnets use magnetic materials like Iron.
b . An electromagnet can be changed by changing the amount of current.
In an electromagnet, the magnetic field is generated by an electric current in a coil of wire which reinforces an iron core. But when the electric current applied on the mentioned core is disconnected, it immediately loses its magnetization. This also means that the intensity of the magnetic field can be controlled (increased or decreased) by changing the intensity of the electric current flowing through the nucleus.
On the other hand, the permanent magnet does not depend on electric current to magnetize, because due to its composition (a ferromagnetic material) the magnetization capacity continues even after not being in contact with an external magnetic field.
all of the above
a i think sorry if its wrong
An electromagnet shows both electric as well as magnetic property, and the materials comprising this type of property is mainly made up of a coil of insulated wire that is tied around a magnetic. When the current is allowed to pass through it, then it behaves as a magnet.
On the other hand, permanent magnet refers to those substances that are comprised of magnetized materials, and due to this, they have the ability to create a magnetic field of their own. These magnetic property shown by these substances are permanent and it remains for a long time.
an electromagnet wave can go through objects
C) Electromagnets are only magnetized when a current flows through a wire wrapped around the core.
An electromagnet is a magnet that runs on electricity. Unlike a permanent magnet (bar magnet), amount of electric current that flows through electromagnet changes the strength of an electromagnet. The poles of an electromagnet are determined by flow of electricity.
this was wrong
answers.com says temperate reagions