1.
Earth's magnetic fields are __________ at poles.
Explanation
Earth's magnetic fields are strongest at the poles because the magnetic field lines converge at the poles, creating a concentrated and intense magnetic field. This is due to the Earth's magnetic field being generated by the movement of molten iron in its outer core. As the molten iron circulates, it creates electric currents that generate the magnetic field. The convergence of field lines at the poles results in a stronger magnetic field compared to other regions on Earth.
2.
Check at least two ways to increase the strength of an electromagnet.
Correct Answer(s)
A. Make loops tighter
D. Use iron
Explanation
Making the loops tighter in an electromagnet increases its strength because it increases the number of turns in the coil, which in turn increases the magnetic field produced. Using iron also increases the strength of an electromagnet because iron is a ferromagnetic material that enhances the magnetic field.
3.
True or False. Electricity is created when electrons are moving.
Correct Answer
A. True
Explanation
Electricity is created when electrons are moving. This is because electricity is the flow of electrons through a conductor. When there is a potential difference (voltage) applied across a conductor, the electrons are pushed and start moving, creating an electric current. So, the statement "Electricity is created when electrons are moving" is true.
4.
What do you need to make an electromagnet?
Correct Answer
B. Iron
Explanation
To make an electromagnet, you need iron. Iron is a ferromagnetic material, which means it can be easily magnetized. When an electric current passes through a coil of wire wrapped around the iron core, it creates a magnetic field, turning the iron into a magnet. This allows the electromagnet to attract and repel other magnetic objects.
5.
A magnetic ________ is when all magnetic fields are lined up in the SAME way.
Correct Answer
domain, DOMAIN
Explanation
A magnetic domain is a region within a material where the magnetic fields of atoms or molecules are aligned in the same direction. This alignment creates a stronger overall magnetic field within the domain. When all the magnetic fields in a material are lined up in the same way, it is referred to as a magnetic domain. The correct answer is "domain, DOMAIN" because it accurately describes the concept of aligned magnetic fields within a material.
6.
What is an electromagnet? Check one box.
Correct Answer
C. A core strong temporary magnet
Explanation
An electromagnet is a temporary magnet that is created by passing an electric current through a coil of wire. The coil of wire, also known as the core, becomes magnetized when the electric current flows through it, creating a magnetic field. This magnetic field can attract or repel other magnets or magnetic materials. Unlike a permanent magnet, an electromagnet only exhibits magnetic properties when the electric current is flowing through it.
7.
___________ - is an attraction of magnet for another object.
Correct Answer
D. Magnetism
Explanation
Magnetism is the attraction of a magnet for another object. It is a force that causes certain materials, such as iron or steel, to be attracted to magnets. Magnetism is caused by the alignment of electrons in the material, creating a magnetic field. This magnetic field then interacts with the magnetic field of the magnet, resulting in the attraction between the two objects.
8.
____________ - is force around a magnet.
Correct Answer
C. Magnetic field
Explanation
A magnetic field is the force around a magnet. It is the area in which a magnetic force can be detected and is created by the movement of electric charges. This force can attract or repel other magnets or magnetic materials. Magnetic fields play a crucial role in various applications, such as generating electricity in power plants, operating electric motors, and guiding compass needles.
9.
Is a pernament made out of a magnetic field?
Correct Answer
B. False
Explanation
A permanent magnet is made out of a material that can retain its magnetism over a long period of time. It is not made out of a magnetic field itself. The magnetic field is created by the alignment of the magnetic domains within the material. Therefore, the statement that a permanent magnet is made out of a magnetic field is incorrect.