Physics and Math - Electrostatics and Magneteism

MCAT Chapter 5

Proton

positive charge

Electron

negative charge

What forces opposite charges attract

attractive forces

What forces like charges exert

repulsive forces

Ground

A means fo returning charge to earth

Insulators

does not easily distribute charge over its surface and will not transfer that charge to another neutral object very well

Conductors

When given charge will distribute approximately evenly upon the surface of conductor

Field Lines

imaginary lines represent how a positive test charge would move in the presence of the source charge

Electric Potential Energy

work necessary to move a test charge from infinity to a point in space in an electric field surrounding a source charge

Electrical potential

ratio of the magnitude of a charges electric potential energy to the magnitude of charge itself

Equipotential line

Line on which potential at every point is the same

Electron dipole

Results from two equal if opposite charges being separated a small distance from eachother

Perpindicular bisector of the dipole

equipotential line lies halfway between +q and -q, the electrical potential is zero

Diamagnetic Materials

made of atoms with no unpaired electrons and that have no net magnetic field

Examples of diamagnetic materials

wood plastic water glass

Paramagnetic Materials

unpaired electrons so atoms have net magnetic dipole, will become weakly magnified in presence of external magnetic field, aligning the magnetic dipoles of the material with external field. Upon removal of external field, thermal energy of individual atoms will cause individual magnetic dipoles to reorrient

examples of paramagnetic materials

aluminum copper gold

Ferromagnetic Materials

unpaired electrons and permenant atomic magnetic dipoles that are normally oriented randomly so that the material has no net magnetic dipole, become strongly magnetified when exposed to magnetic field or under certain temps

Ferromagnetic Materials examples

Iron Nickel Cobalt

Lorentz Force

Sum of electrostatic and magnetic force