Magnetism

• Magnetism - Ability of a magnetic material to attract other magnetic materials.
• Magnet - Material possessing magnetic ability.
• The atoms of a magnetic material is a magnet itself.
• These atoms arranged themselves into group called magnetic domain
• Ferromagnetic materials - Strongly attracted by a magnet.
• Paramagnetic Materials - Weakly attracted by a magnet. Becomes more magnetic when cooled.
• Diamagnetic Materials _ Weakly responds to magnetic field. Magnetization occurs only when an external magnetic field is applied
• Pole - Region of a magnet, usually near it ends, where magnetic force the greatest and emitted.
• Magnetic Field - A region of space where a magnet is capable of exerting a magnetic force.
• North and South ALWAYS come together.
• Magnetic Monopole – single magnetic poles (never observed)
• The biggest magnet on Earth is Earth itself.
• Due to the motion of charged particles in its liquid core
• Earth magnetic axis is not exactly parallel to the geographic axis.
• Magnetic Declination - The slight difference reading of compass and actual direction.
• Magnetic Inclination - Region near North and South pole where the angle of the magnetic field is vertically upward.
• ELECTRIC CURRENT generates MAGNETIC FIELD.
• A moving charge generates magnetic field which affects the space around it.
• The magnetic field exerts a force onto other charges moving around that magnetic field known as magnetic force.
• Magnetic force, velocity, and magnetic field are perpendicular to each other.
• Magnetic force is perpendicular to the plane where the charge is moving at a certain velocity and the magnetic field.
• Oersted's Discovery Formula: F qvB sin theta
• A straight current-carrying wire produces concentric circular magnetic field lines around the wires.
• Thumb points toward the direction of the current and the other finger follow the direction of the magnetic field.
• Magnetic field is produced at the axis along the center of the loop.
• Solenoid is the magnetic field is similar to that a bar magnet.
• Magnetic Flux - Number of field lines that passes through a surface.
• Magnetic Flux Formula: Magnetic Flux = BA cos theta
• there is a max flux f the surface and lines are perpendicular
• there is zero flux if the surface and lines are parallel
• the flux of an angled surface is: BA cos theta
• Magnetic flux through a closed surface is zero because the field lines entering the surface is equal to the field lines leaving the surface.