The study of distribution of fixed/stationary charges or electrons at rest.

The process of electron charges being added or subtracted from an object (usually neutral).

Charge is a property of ____.

Electrical charges are measured in the System International (SI) unit ____.

Some materials, such as copper & gold, have a very large number of electrons free to move about, making them good ____ of electricity.

Glass & plastic have very few free electrons, making them good ____.

What are the 5 Laws of Electrostatics?

Like charges repel each other, unlike charges attract each other.

The electrostatic force between two charges is directly proportional to the product of their quantities & inversely proportional to the square of the distance between them.

Electric charges will reside only on the outside surfaces of a conductor, as they are repelling each other.
***They will reside all throughout a non-conductor.***

The greatest ____ of charges will be on the surface where the curvature is greatest.

Only negative charges (electrons) will move along solid conductors.
**Positive charge (protons) are 2000 times heavier than electrons.**

3 Methods of Electrification in Electrostatics:

Occurs when one object is rubbed against another causing one object to acquire more electrons & the other to lose electrons.

Occurs when two objects touch allowing electrons to transfer from one object to another.

Electrons transfer without any contact.

The study of electric charges in motion & what we most often consider as "electricity."

No atoms to oppose electron movement.

Promote the flow of electrons.

Creates a medium for electrons to migrate from one pole to another.

Any metal that allows current flow is a conductor.

Pathway that permits electron movement from one point, through a wire, & then back to that point.

_____ creates a separation of charges & the exposure factors the radiographer selects on the control panel to determine the # of electrons that will flow & the magnitude of their attraction to the positive side.

The ability to do work due to a separation of charges.

What is the unit of measure for electric potential?

An expression of the flow of electrons in a conductor.

Unit of measure for a current.

The property of an element in a circuit that resists or impedes the flow of electricity.

What's the unit of measure for resistance?

____ is defined as the potential difference that will maintain a current of 1 ampere in a circuit with a resistance of 1 ohm.

The ___ is defined as 1 coulomb flowing by a given point in 1 second.

Electrons always move from the point of ____ concentrations to lowest.

-Flows only in one direction
-Example: Batteries

-Changes direction in cycles as the electric potential of the source changes.
-Example: The electricity in homes in the United States.

Both ___ & ___ are used in basic x-ray production.

Defined as the quantity, or number, or electrons flowing per second.

Defined as the force with which the electrons travel through the circuit.

Defined as the amount of opposition to the current in the circuit.

The mathematical relationship between current, potential difference, & resistance.

Materials with an abundance of free electrons that allow a relatively free flow of electricity.
(Gold, Copper)

Materials made up of atoms with tightly bound electrons that do not conduct electricity well even when attracted by a potential difference.
(Glass/Rubber/Plastic)

Materials that will conduct electricity but not as well as conductors & that will insulate but not as well as insulators.
(Silicone)

The ____ (Longer/Shorter) the conductor, the more resistance.

___ ___ states that the potential difference (voltage) across the total circuit or any part of that circuit is equal to the current (amperes) multiplied by the resistance.

The (larger/smaller) ____ the diameter, the less resistance.

A closed (complete) pathway for electricity is required for electricity to flow.

An open (Broken) pathway, such as occurs when a switch is turned off.

Circuit elements are wired along a single conductor.

Circuit elements "bridge" or branch across a conductor.

Produces electrons through a chemical reaction, stores an electric charge long term, & provides an electric potential.

Temporarily stores an electric charge.

A "one-way valve" device, allows electrons to flow in one direction.

The ____ in Ohm's is equal to the sum of each separate resistor.

The ____ equals the sum of each separate voltage for resistor.

____ across each resistor equals the current times the individual resistor.

In a series circuit, the ___ stays the same..

In a parallel circuit, the ___ stays the same.

The process of connecting an electrical device to the earth via a conductor.

Ability of a material to attract iron, cobalt, nickel.

The nature of magnetic materials is that the orbital electrons of their atoms spin in predominately ____ direction.

A magnetic field consists of lines of force in space.

Inside the magnetic, the flux goes from ____ to ____ direction when there is a Direct Current.

Outside the magnet, the flux goes from ____ to ____ direction when there is a direct current.

The 3 Laws of Magnetism

The 3 Types of Magnets:

The strength of the magnetic field is measured in the SI unit ___.

Examples of nonmagnetic materials that are not attracted to the magnetic field?

Examples of diamagnetic materials that are weakly repelled by magnetic fields.

Examples of Paramagnetic materials that are weakly attracted to magnetic field.

Examples of Ferrimagnetic materials that are strongly attracted magnetic materials.

Magnetic materials that are:
-High Permeability
-Magnetic Materials
-Iron, Nickel, Cobolt
-Highly susceptible to induction.

-Low Permeability
-Platinum & Aluminum
-Weak attraction to magnetic fields

-Weakly repelled by magnetic fields
-Beryllium, Bismuth, Lead, & Water

-Not attracted by a magnet
-CANNOT be magnetized
-Wood, plastic, glass
-Most materials on non-magnetic.

Electricity & Magnetism are two parts of the same basic force.
-Any flow of electrons, whether in space or in a conductor, will be surrounded by a magnetic field.
-A moving field can create an electric current.

Devices that convert some form of mechanical energy into electrical energy.

Moving conductor through a magnetic field induces an electric current in that conductor.

Process by which a magnetic field induces a current in the same wire & created a resistance within the circuit.

Coverts electrical to mechanical energy through electromagnetic induction.

What devices controls electrical voltage & current?

A step-up transformer (Increases/Decreases) ____. voltage.

A step-down transformer (Increases/Decreases) ____ voltage.

Types of transformers:

The x-ray circuit may be divided into 3 sections:

The main power switch is simply an on-off switch for the unit & is connected to the power supply of the facility.

Device usually wired to the autotransformer that automatically adjusts the power supplied to the x-ray machine to 220 volts.

Protect against short circuits & electric shock.

An adjustable transformer controlled by the kilovolt peak (kVp) elector on the control panel.

Primary & secondary coils are filled with an iron core to increase the strength of the magnetic field.

Two coils of wire in proximity to facilitate induction.

Closing the core by placing a top & bottom on the iron cores.

Consists of the secondary side of the step-up transformer, the mA meter, a rectifier bank, & the X-ray tube.

Consists of rheostat, a step-down transformer, & the filaments.

Rectifier changes the ___ to ___.

This increases the heating capacity of the X-ray tube thus permitting larger exposures.

Back-up mAs should at least be set at ____%.

When using the AEC, you should only be adjusting the ___ on the control panel.

____ always flow from cathode to anode.

The diodes permit the flow of the electrons from cathode to anode through the X-ray tube.
(HALFWAVE RECTIFICATION)

The diodes suppress the negative half of the AC cycle by acting as a non-conductor or an open switch & this prevents the electrons from flowing toward the anode.
(HALFWAVE RECTIFICATION)

Current will flow through a rectifier then the tube, then another rectifier to the secondary of the transformer.
(FULLWAVE RECTIFIER)

The current reverses & will flow through the rectifiers that were not used during the positive half of the cycle & also through the tube.
(FULLWAVE RECTIFIER)

When four rectifiers are used, ___wave rectification is achieved.

The final & last section to the x-ray circuit.

The second part of the x-ray circuit.

___ phase allows the potential difference to drop to zero with every change in direction of the current flow.

In a ___ wave rectifier circuit, this means the X-ray tube is experiencing no potential difference & is producing no x-ray photon 120 times every sec.

The amount of fluctuation in the voltage of the power to an x-ray machine.
For x-ray machines, the less ripple, the better.

Supplies power to the X-ray tube so that the filament supplies enough electrons by the thermionic emission.

Supplies power to the X-ray tube so that x-rays are produced.

The switch that generates the power to the X-ray tube.

A remote control device that permits current flow through the circuit.

Device used to end the exposure at an accurately measured preset time.

This is where the alternating current comes from to power the circuit

This is where you adjust the kVp for the exposure.

This part of the circuit stops the exposure.

This transformer bumps the voltage up so that the X-ray tube has a very high voltage to make the electrons have enough energy to form x-rays.

This makes the current only go in one direction through the X-ray tube.

This variable resistor adjusts the current going to the filament.

This transformer steps the voltage down & therefore the current up.

This is where the x-rays are created.

This rotates the anode.

Suppresses the negative to protect the X-ray tube.
Only used in dental.

Reverses negative pulses to make the positive.
Reduces exposure time by 1/2

Six pulses per cycle.
A lot more output.

Twelve Pulses per cycle.
The greater photon output has greater (higher) energy.
Even more output

Greatest output
Lowest Dose to pt.
High energy & short exposure times

When four rectifiers are used: