10577929
Description
Flashcards by Alex Ertmer, updated more than 1 year ago
|
Created by Alex Ertmer
over 6 years ago
|
|
| Question | Answer |
| The study of distribution of fixed/stationary charges or electrons at rest. | Electrostatics |
| The process of electron charges being added or subtracted from an object (usually neutral). | Electrification |
| Charge is a property of ____. | Matter |
| Electrical charges are measured in the System International (SI) unit ____. | Coulomb |
| Some materials, such as copper & gold, have a very large number of electrons free to move about, making them good ____ of electricity. | Conductors |
| Glass & plastic have very few free electrons, making them good ____. | Insulators |
| What are the 5 Laws of Electrostatics? | 1)Repulsion/Attraction 2)Inverse Square Law 3)Distribution 4)Concentration 5)Movement |
| Like charges repel each other, unlike charges attract each other. | Repulsion/Attraction |
| 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. | Inverse Square Law |
| 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.*** | Distribution |
| The greatest ____ of charges will be on the surface where the curvature is greatest. | Concentration |
| Only negative charges (electrons) will move along solid conductors. **Positive charge (protons) are 2000 times heavier than electrons.** | Movement |
| 3 Methods of Electrification in Electrostatics: | 1)Friction 2)Contact 3)Induction |
| Occurs when one object is rubbed against another causing one object to acquire more electrons & the other to lose electrons. | Friction |
| Occurs when two objects touch allowing electrons to transfer from one object to another. | Contact |
| Electrons transfer without any contact. | Induction |
| The study of electric charges in motion & what we most often consider as "electricity." | Electrodynamics |
| No atoms to oppose electron movement. | Vacuum |
| Promote the flow of electrons. | Gases |
| Creates a medium for electrons to migrate from one pole to another. | Ionic Solutions |
| Any metal that allows current flow is a conductor. | Metallic Conductors |
| Pathway that permits electron movement from one point, through a wire, & then back to that point. | Electric Circuit |
| _____ 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. | X-ray tube |
| The ability to do work due to a separation of charges. | Electric Potential |
| What is the unit of measure for electric potential? | Volt |
| An expression of the flow of electrons in a conductor. | Current |
| Unit of measure for a current. | Ampere |
| The property of an element in a circuit that resists or impedes the flow of electricity. | Resistance |
| What's the unit of measure for resistance? | Ohm |
| ____ is defined as the potential difference that will maintain a current of 1 ampere in a circuit with a resistance of 1 ohm. | Volt |
| The ___ is defined as 1 coulomb flowing by a given point in 1 second. | Ampere |
| Electrons always move from the point of ____ concentrations to lowest. | Highest |
| -Flows only in one direction -Example: Batteries | Direct Current (DC) |
| -Changes direction in cycles as the electric potential of the source changes. -Example: The electricity in homes in the United States. | Alternating Current (AC) |
| Both ___ & ___ are used in basic x-ray production. | Alternating Current (AC) & Direct Current (DC) |
| Defined as the quantity, or number, or electrons flowing per second. | Current |
| Defined as the force with which the electrons travel through the circuit. | Potential Difference |
| Defined as the amount of opposition to the current in the circuit. | Resistance |
| The mathematical relationship between current, potential difference, & resistance. | Ohm's Law |
| Materials with an abundance of free electrons that allow a relatively free flow of electricity. (Gold, Copper) | Conductors |
| 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) | Insulators |
| Materials that will conduct electricity but not as well as conductors & that will insulate but not as well as insulators. (Silicone) | Semiconductors |
| The ____ (Longer/Shorter) the conductor, the more resistance. | Longer/More |
| ___ ___ 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. | Ohm's Law |
| The (larger/smaller) ____ the diameter, the less resistance. | Larger |
| A closed (complete) pathway for electricity is required for electricity to flow. | Closed Circuit |
| An open (Broken) pathway, such as occurs when a switch is turned off. | Open Circuit |
| Circuit elements are wired along a single conductor. | Series Circuit |
| Circuit elements "bridge" or branch across a conductor. | Parallel Circuit |
| Produces electrons through a chemical reaction, stores an electric charge long term, & provides an electric potential. | Battery |
| Temporarily stores an electric charge. | Capacitor |
| A "one-way valve" device, allows electrons to flow in one direction. | Diode |
| The ____ in Ohm's is equal to the sum of each separate resistor. | Total Resistance |
| The ____ equals the sum of each separate voltage for resistor. | Total Voltage |
| ____ across each resistor equals the current times the individual resistor. | Voltage |
| In a series circuit, the ___ stays the same.. | Current |
| In a parallel circuit, the ___ stays the same. | Voltage |
| The process of connecting an electrical device to the earth via a conductor. | Grounding |
| Ability of a material to attract iron, cobalt, nickel. | Magnetism |
| The nature of magnetic materials is that the orbital electrons of their atoms spin in predominately ____ direction. | One |
| A magnetic field consists of lines of force in space. | Flux |
| Inside the magnetic, the flux goes from ____ to ____ direction when there is a Direct Current. | South to North |
| Outside the magnet, the flux goes from ____ to ____ direction when there is a direct current. | North to South |
| The 3 Laws of Magnetism | 1) Every magnet has a north/South Pole. 2)Like poles repel each other & opposite poles attract each other. 3)The force & attraction or repulsion varies directly with the strength of the poles & inversely with the square of the distance between them. |
| The 3 Types of Magnets: | 1)Natural 2)Artificial 3)Electromagnets |
| The strength of the magnetic field is measured in the SI unit ___. | Tesla (T) |
| Examples of nonmagnetic materials that are not attracted to the magnetic field? | Glass Wood Plastic |
| Examples of diamagnetic materials that are weakly repelled by magnetic fields. | Water Mercury Gold |
| Examples of Paramagnetic materials that are weakly attracted to magnetic field. | Platinum Gadolinium Aluminum |
| Examples of Ferrimagnetic materials that are strongly attracted magnetic materials. | Iron Cobalt Nickel |
| Magnetic materials that are: -High Permeability -Magnetic Materials -Iron, Nickel, Cobolt -Highly susceptible to induction. | Ferromagnetic Materials |
| -Low Permeability -Platinum & Aluminum -Weak attraction to magnetic fields | Paramagnetic Materials |
| -Weakly repelled by magnetic fields -Beryllium, Bismuth, Lead, & Water | Diamagnetic Materials |
| -Not attracted by a magnet -CANNOT be magnetized -Wood, plastic, glass -Most materials on non-magnetic. | Non-Magnetic Materials |
| 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. | Electromagnetism |
| Devices that convert some form of mechanical energy into electrical energy. | Electric Generators |
| Moving conductor through a magnetic field induces an electric current in that conductor. | Electromagnetic Induction |
| Process by which a magnetic field induces a current in the same wire & created a resistance within the circuit. | Self-Induction |
| Coverts electrical to mechanical energy through electromagnetic induction. | Motors |
| What devices controls electrical voltage & current? | -Transformers -Autotransformers -Capacitors |
| A step-up transformer (Increases/Decreases) ____. voltage. | Increases |
| A step-down transformer (Increases/Decreases) ____ voltage. | Decreases |
| Types of transformers: | -Air Core -Open Core -Closed Core -Shell Type |
| The x-ray circuit may be divided into 3 sections: | 1) Primary Circuit 2) Secondary Circuit 3) Filament Circuit |
| The main power switch is simply an on-off switch for the unit & is connected to the power supply of the facility. | Primary Circuit |
| Device usually wired to the autotransformer that automatically adjusts the power supplied to the x-ray machine to 220 volts. | Line Compensator |
| Protect against short circuits & electric shock. | Circuit Breakers |
| An adjustable transformer controlled by the kilovolt peak (kVp) elector on the control panel. | Autotransformer |
| Primary & secondary coils are filled with an iron core to increase the strength of the magnetic field. | Open Core |
| Two coils of wire in proximity to facilitate induction. | Air Core |
| Closing the core by placing a top & bottom on the iron cores. | Closed Core |
| Consists of the secondary side of the step-up transformer, the mA meter, a rectifier bank, & the X-ray tube. | Secondary Circuit |
| Consists of rheostat, a step-down transformer, & the filaments. | Filament Circuit |
| Rectifier changes the ___ to ___. | AC & DC |
| This increases the heating capacity of the X-ray tube thus permitting larger exposures. | Rectifier/Diode |
| Back-up mAs should at least be set at ____%. | 150% |
| When using the AEC, you should only be adjusting the ___ on the control panel. | kVp |
| ____ always flow from cathode to anode. | Electrons |
| The diodes permit the flow of the electrons from cathode to anode through the X-ray tube. (HALFWAVE RECTIFICATION) | Positive Half |
| 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) | Negative Half |
| Current will flow through a rectifier then the tube, then another rectifier to the secondary of the transformer. (FULLWAVE RECTIFIER) | Positive Half |
| 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) | Negative Half |
| When four rectifiers are used, ___wave rectification is achieved. | Fullwave |
| The final & last section to the x-ray circuit. | Filament Circuit |
| The second part of the x-ray circuit. | Secondary Circuit |
| ___ phase allows the potential difference to drop to zero with every change in direction of the current flow. | Single Phase |
| 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. | Fullwave |
| The amount of fluctuation in the voltage of the power to an x-ray machine. For x-ray machines, the less ripple, the better. | Voltage Ripple |
| Supplies power to the X-ray tube so that the filament supplies enough electrons by the thermionic emission. | Filament Circuit |
| Supplies power to the X-ray tube so that x-rays are produced. | Main Part of X-ray Circuit |
| The switch that generates the power to the X-ray tube. | Main Switch |
| A remote control device that permits current flow through the circuit. | Exposure Switch |
| Device used to end the exposure at an accurately measured preset time. | Timer |
| This is where the alternating current comes from to power the circuit | Main Breaker |
| This is where you adjust the kVp for the exposure. | Autotransformer |
| This part of the circuit stops the exposure. | Timer Circuit |
| 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. | High-Voltage Step-Up Transformer |
| This makes the current only go in one direction through the X-ray tube. | Four-Diode Rectification Circuit |
| This variable resistor adjusts the current going to the filament. | Filament Circuit Variable Resistor |
| This transformer steps the voltage down & therefore the current up. | Filament Step-Down Transformer |
| This is where the x-rays are created. | X-ray tube |
| This rotates the anode. | Rotor Stator |
| Suppresses the negative to protect the X-ray tube. Only used in dental. | Single Phase One-Pulse (Halfwave Rectified) |
| Reverses negative pulses to make the positive. Reduces exposure time by 1/2 | Single Phase Two Pulse (Fullwave Rectified) |
| Six pulses per cycle. A lot more output. | Three Phase Six Pulse |
| Twelve Pulses per cycle. The greater photon output has greater (higher) energy. Even more output | Three Has Twelve Pulse |
| Greatest output Lowest Dose to pt. High energy & short exposure times | High Frequency |
| When four rectifiers are used: | Full-wave Rectification is achieved |
Want to create your own Flashcards for free with GoConqr? Learn more.