ELECTRICITY
The purpose of an X-ray unit is to convert electric energy into:
ELECTROMAGNETIC ENERGY of the x-ray beam
TYPES OF ELECTRIC ENERGY CONVERSION
Recharging a car battery converts electric energy into chemical energy
table saw converts into mechanical energy
Kitchen appliances converts to thermal energy
ELECTROSTATICS
Matter has:
mass
form
energy
(may also have:)electric charge
ELECTRIC CHARGE
Positive and negative
Electron and Proton
ELECTRON AND PROTON
Electrons can travel from outer shell of one atom to another easily
Protons cannot travel easily or at all because they are fixed in the nucleus
THEREFORE:
ELECTRIC CHARGE IS PRIMARILY ASSOCIATED WITH ELECTRONS
ELECTROSTATICS
The study of electric charges in stationary form.
Static electricity!!!
ELECTRIFICATION
ELECTRIFIED!!!
An object which as too many or two few electrons is considered to be electrified.
"The transfer of electrons from one object to another causes the first object to be positively electrified and the second object to be negatively electrified" page 72
CAUSES OF ELECTRIFICATION
Contact
Friction
Induction
Person to object
Balloon
Lightning
GROUND
Electrically neutral object which acts as a reservoir for electric charges
COULOMB (C)
Because the charge of an electron is too small to measure, a fundamental measuring unit for electric charge is 1 C or
6.3 x 10 to the eighteenth power electron charges
ELECTROSTATIC LAWS
Like charges repel
unlike charges attract
Both form an electric field
Positive field radiates outward
Negative field radiate inward
ELECTOSTATIC FORCE IS THE REPULSION OR ATTRACTION BETWEEN CHARGES DUE TO THE ELECTRIC FIELD
COULOMB’S LAW:
THE GREATER THE ELECTROSTATIC CHARGES FOR EITHER OBJECT, THE GREATER THE
ELECTROSATIC FORCE
COULOMB’S LAW:
THE FORCE IS STRONGER WHEN OBJECTS ARE CLOSER, WEAKER WITH THE INCREASE OF
DISTANCE
ELECTRIC CHARGE DISTRIBUTION
ELECTRIC CHARGES ARE UNIFORMLY DISTRIBUTED THROUGHOUT THE OBJECT OR ON ITS SURFACE
ELECTRIC CHARGE CONCENTRATION
THE ELECTRIC CHARGE OF A CONDUCTOR IS CONCENTRATED ALONG THE SHARPEST CURVATURE OF ITS SURFACE.
ELECTRODYNAMICS
WHAT IS IT?
Study of Charges in Motion
AKA: Electricity!!!!!!
FLOW OF ELECTRONS=ELECTRIC CURRENT
THE FLOW THE ELECTRONS IS OPPOSITE THE CURRENT
ELECTRONS FLOW EASILY THROUGH CONDUCTORS
Insulators impede the flow of electrons.
Semiconductors do both!!
Superconductivity: some material display no resistance below a critical temperature
Four States of Electrical Matter
Superconductor
Conductor
Semiconductor
Insulator
Electric Circuits
Electrons flow along outer surface of wire. When the path is closed and resistance can be controlled, this is known as an electric circuit.