Physics Magnetism Flashcards

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Questions and Answers

What is magnetism?

The force exerted by magnets when they attract or repel each other.

What is magnetism caused by?

The motion of electric charges.

What causes magnetism inside the atom?

The electrons that are in constant motion around the nucleus of an atom.

Why are unpaired electrons more significant than paired electrons in terms of magnetic properties?

Unpaired electrons have a magnetic field. Signup and view all the answers

What causes a material to be classified as 'ferromagnetic'?

Ferromagnetic materials are very attracted to other magnetic fields. Signup and view all the answers

Name some examples of ferromagnetic materials.

Iron, nickel, and cobalt. Signup and view all the answers

What is a magnetic domain?

A small region within ferromagnetic materials. Signup and view all the answers

What is basalt and how do scientists use it to determine the direction of Earth's magnetic field over time?

Basalt is a rock formed from solidified lava, which is slightly magnetic. Signup and view all the answers

How does geomagnetism help scientists understand the motion of Earth's plates?

It records the Earth's magnetic field as lava solidifies. Signup and view all the answers

What is magnetic declination and what causes it?

The angle between magnetic north and true north. Signup and view all the answers

What do the terms 'geographic north' and 'magnetic north' mean?

Magnetic North is the North of Earth's magnetic field, whereas geographic North is true North. Signup and view all the answers

When will magnets attract or repel each other?

Opposites attract. Signup and view all the answers

What happens when you cut a magnet in half?

You get 2 smaller magnets. Signup and view all the answers

What are magnetic field lines?

They illustrate the magnitude and direction of a magnetic field. Signup and view all the answers

What is the right hand rule?

Procedure for identifying the direction of an angular motion vector. Signup and view all the answers

What is the unit in a magnetic field?

Tesla (T). Signup and view all the answers

What are permanent magnets?

Magnets created by moving charge, made from ferromagnetic materials. Signup and view all the answers

In a bar magnet, where is the magnetic field strongest?

Inside the magnetic material. Signup and view all the answers

In a bar magnet, where are the strongest external magnetic fields?

Near the poles. Signup and view all the answers

What is the direction of the electric field of a point charge from a positive charge?

Radially outward. Signup and view all the answers

Why do electrons act like microscopic magnets?

Electrons in atoms circle a nucleus, which generates an electric current. Signup and view all the answers

What are geomagnetic poles?

The points on the Earth's magnetic field. Signup and view all the answers

What is the magnetosphere?

The area surrounding Earth that is influenced by Earth's magnetic field. Signup and view all the answers

What is solar wind?

Charged particles from the sun. Signup and view all the answers

The magnetosphere protects the earth from ______________, but some leak through and become trapped.

solar wind particles. Signup and view all the answers

How are auroras produced?

Particles from the solar wind hit atoms of gas in the upper atmosphere around geomagnetic poles. Signup and view all the answers

What is an electromagnet?

A coil that has a soft iron core and acts as a magnet when an electric current is in the coil. Signup and view all the answers

What is electric current?

The continuous flow of electric charges through a material. Signup and view all the answers

Study Notes

Magnetism Overview

Magnetism: A force by magnets that can attract or repel each other.
Caused by the motion of electric charges.

Atomic Magnetism

Magnetism at the atomic level is due to electrons moving around the nucleus, producing a magnetic field.
Unpaired electrons create a magnetic field, while paired electrons do not influence magnetic properties.

Ferromagnetism

Ferromagnetic materials (e.g., iron, nickel, cobalt) can be strongly attracted to magnetic fields and retain magnetism after the external field is removed.
Magnetic domains: Small regions in ferromagnetic materials that align to produce magnetism.

Geological Applications

Basalt: A rock formed from solidified lava, which records Earth's magnetic field direction during solidification, useful for tracking historical magnetic field changes.
Geomagnetism aids in understanding tectonic plate motion, as lava emerging from mid-ocean ridges records the magnetic field, acting like a tape recorder.

Magnetic Measurements

Magnetic declination: The angle between magnetic north (the direction of a compass needle) and true north.
Geographic North is the true north, while Magnetic North refers to the orientation of the Earth's magnetic field.

Magnet Interactions

Magnets attract or repel each other based on their poles: opposite poles attract, like poles repel.
Cutting a magnet in half results in two smaller magnets, each with their own north and south poles.

Magnetic Field Properties

Magnetic field lines illustrate the magnitude and direction of a magnetic field, represented as closed loops.
The strongest magnetic field in a bar magnet is found inside the material, while the strongest external fields are near the poles.

Electromagnetism

Permanent magnets are made from ferromagnetic materials and created by moving charges.
An electromagnet consists of a coil with a soft iron core that acts as a magnet when an electric current flows through it.

Electric Fields and Charges

The electric field direction from a positive point charge is radially outward.
Electrons behave like microscopic magnets due to their movement around the atomic nucleus, generating electric currents.

Earth's Magnetosphere

The magnetosphere encompasses the area surrounding Earth affected by its magnetic field, protecting it from solar wind particles.
Although the magnetosphere blocks most solar wind, some particles can leak through, becoming trapped.
Auroras occur when solar wind particles collide with gas atoms in the upper atmosphere near geomagnetic poles.

Units of Measurement

The unit of measurement for magnetic fields is the Tesla (T).

Right Hand Rule

A technique, known as the right hand rule, is used to determine the direction of an angular motion vector in physics.

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Description

Test your knowledge of magnetism with these flashcards. Each card presents key terms and definitions related to the concepts of magnetism, including forces and atomic structure. Perfect for students studying physics or revising for exams.