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Deangelis review
deangelis questions
| Question | Answer |
|---|---|
| A neutral atom that loses an electron by ionization is a | Positive ion |
| The highest bonding energy of an atom is founf in the electron's __ level | first energy orbital |
| An electron with a lowest binding energy is most likely located in the | M shell |
| The rubbing of fur and amber or silk with glass result in electrification by a process called | Friction |
| Any material which tend to oppose the flow of electrons are termed | Non-conductors & Insulators |
| The transfer of same charge to an uncharged object by placing the two objets in contact with each other is | Conduction |
| Electrification may occur from these 2 processes | Conduction & Friction |
| In a solid conductor, current consists of a flow of moving | Electrons |
| The Electostatic force between two charged objects is __ proportional to the ___ of the distance between them | Inversely, square |
| The force within an electrical circuit most responsible for the movement of current is termed the: | Potential difference |
| The resistance of a wire is related to its: | Length, temp, cross-sectional area |
| A capacitor, condenser, & battery all: | are a device used for storage of electricity |
| The amount of electrical potential, or potential defference in an electrical circuit, is measured by a unit called | Volt |
| An electromagnetic device consisting of a single iron core surrounded by a wire carrying current is termed a | Electromagnet |
| The production of electricity by the rotation of a coil of wire within a stationary magnetic field is | Electromagnetic induction |
| In a magnet the individual magnetic domains are aliged in | single direction |
| The ability of a magnetic material to resist demagnetization is | retentivity |
| v= R= I= | V=IR R=V/I I=V/R |
| A line voltage compensator is incorporated into the primary circuit of a modern radiographic unit to | Maintain a constant KVP level |
| Meter that is used to measure the current passing between the elctrodes of an x-ray tube is the | Milliammeter-seconds meter |
| T/F The filament selector is not found in the high-tension portion of a modern x-ray circuit | True |
| Oil within the sealed housing of the x-ray tube is for | Cooling and electrical insulation |
| This change would be associated with a higher amount of current passing through the filament of the x-ray tube | The selection of a higher mA station |
| The Autotransformer and timer switch are likely found in the | primary circuit |
| The high temps that are needed to produce the therionic emission in the filament of an x-ray tube require a current of about: | 4-6 amps |
| The current passing between the secondary of the high tension transformer and the rectifiers is best described as a type of | High voltage(kv) AC |
| T/F Rectifiers & High-tension transformers are current regulating devices required in the production of the high-voltage direct current needed in the x-ray production process | True |
| The main component of a line voltage compensator is a device that is capable of storing small amount of electrical charge called a | Capacitor/ condenser |
| The selection of voltage to the high-tension transformer is most commonly made by adjusting the setting on the | Autotransformer |
| The pre-reading kV meter is incorporated into the xray control panel to measure the potential difference on the | Secondary side of the high tension transformer |
| The most common device used to create the high potential difference(kilovoltage) across the x-ray tube is the high tension | Transformer |
| The reduction of voltage and development of a high amperage by a step-down transformer occurs in the | Filament portion of the circuit |
| In a radiographic unit, the millammeter will register only during the activation of the | Second (exposure) stage of the exposure switch |
| In a modern x-ray circuit, the rectification of high voltage alternating current into pulsating direct current occurs betwen the secondary of the high-tension transformer and the: | x-ray tube |
| In a 3-phase, 6-pulse rectified unit, how many voltage peaks are produced for each cycle of incoming line voltage? | 6 peaks |
| T/F shorter permitted exposures, higher beam quality, & reduced scatter production are all advantages of a 3-phase power supply in xray unit | true |
| The principal material that is used in the formulation of a solid state diode is | silicon |
| In a 3-phase radiographic unit, if one of the rectifiers is damaged prior to a radiographic exposure | a reduced amount of optical density due to a decreased radiation output |
| The process by which alternating current is converted into pulsating direct current is | rectification |
| In a 3-phase, 12-pulse unit, rectification is accomplished by employing | 12 solid state diodes |
| With an alternating current source the electron flow will alternate | 120 times a second |
| A satisfactory radiograph is produced using a 3-phase, 6-pulse unit. If the same technical factors are used on a single-phase unit, the radiograph would show | less focal spot blur |
| T/F A lower radiation exposure to the patient is an advantage of a high frequency generator | false |
| Solid state rectifiers as compared to thermionic diode have/are | More durable more efficient, a longer life |
| Solid state diode is a device most often used for | current rectification |
| The accuracy of a modern electronic exposure timer of a 3-phase radiographic unit which permits exposures as low as 4 milliseconds is best evaluated using an | Oscilloscope or digital timing meter |
| Which type of timer is most commonly employed with most modern 3-phase radiographic units? | Silicon controlled rectifier |
| For safety reasons, the timer circuits for most modern radiographic units are located in the | Primary circuit |
| The termination of the radiographic exposure during an automatic exposure controlled technique is accomplished by a device called | thyristor |
| The main function of the pyrex glass that forms the protective envelop of the x-ray tube is | The containment of the vacuum within the xray tube |
| The principle disadvantage of the use of a smaller focal spot during a radiographic exposure is | The limitation of the amount of mAs that can be applied to the anode |
| speed of rotating anode in 3 phase | 10,000 rpm |
| speed of rotating anode in single phase | 3000 rpm |
| Tungsten is the principal material used in the formation of the | surface of the target rotating anode, stationay anode, & wire used in the helix of the xray tube filament |
| The amount of space charge created at the cathode is primarily contolled by the | impresses amperage |
| In a stationary anode tube, the target is imbedded in an anode made of | copper |
| The unit of power, the watt, is derived from the product of | amperage X voltage |
| The first modern radiographic tube having a heated filament was originally developed in the early 1900's by | william coolidge |
| If the angle on a xray tube anode is decreased from 12 degrees to 7 degrees it will result in a decrease in | size of the focal spot, loading capacity of the tube, field coverage |
| What is the proper sequence of materials traversed by the xray beam after leaving the anode of the xray tube | Pyrex glass, oil, aluminum |
| Angle of the anode and size of the filament will effect the size of the | focal spot |
| As mA increases, blooming of the focal tract results in a | increase in the size of the effective focal spot |
| The material that is often added to a rotating anode disk to reduce surface defects and cracks is called | Rhenium |
| The discovery of xrays was made by wilhelm roentgen in 1895 while experimenting with a partially evacuated glass tube called an | crooke's tube |
| The durability and efficiency of the tungsten filament is often improved by the addition of the metal | thorium |
| The anode of a modern rotating anode tube is generally composed of a combination of tungsten and: | Rhenium & Molybdenum |
| The collective repulsion of the electron cloud around the cathode that creates an equilibrium with the rate of electron emission by the filament is termed the: | Space charge effect |
| The steepness of the anode angle will effect the amount of the: | Anode heel effect, field coverage |
| The general formula that is used to determine the anode heat units created with a fully rectified xray tube is: | HU= mA x kV x time |
| The formation of the space charge in the filament of the xray tube is accomplished during the __ of the normal exposure cycle | Prep or boost |
| T/F The use of a long prep time will help to properly warm up the anode of a modern rotating anode | False |
| The maximum heat storage capacity of the anode of a radiographic tube is related to the: | Diameter of the anode disk, design of the thermal envelope, rotational speed of the anode disk |
| The instantaneous loading capacity rating of the anode is primarily effected by the: | Area of the focal tract |
| A failure to obtain a ready light prior to a radiographic exposure may indicate: | The xray tube is not located at the correct distance from the image receptor |
| Surface irregularities on the face of the anode (pitting) are most often associated with a/an | Reduction in the radiation output during the exposure |
| A __ device can be used to evaluate the accuracy of the timer of a 3-phase radiographic unit | Oscilloscope or digital timing meter |
| A synchronous spin top tester can be used in a quality control program to determine the: | Accuracy of the timing devices in a single-phase rectified system |
| The common indication of a gassy xray tube is __ during the exposure | flucuations in mA readings |
| The life of the filament can be dramatically increased by employing | Lower mA settings |
| Nearly all causes of tube failure are related to the __ of the xray tube | Thermal characteristics of the xray tube |
| The induction motor of a rotating anode is damaged and stops before a series of multiple exposures is made. This will most likely result in | Pitting of the anode |
| The frequency (hertz) of an electromagnetic wave is best defined as the: | Number of oscillations or cycles per second |
| The energy of an electromagnetic radiation is directly proportional to the: | Frequency of the radiation |
| Gamma, x-rays, and ultraviolet rays are members of the ____. | electromagnetic radiation |
| Alpha rays are not part of the electromagnetic radiation. T/F | True |
| If the frequency of an electromagnetic photon is increased by a factor of 4, the wavelength will: | Decrease 4 times |
| The principal unit used to measure the energy of a photon is the: | Electron volt |
| During the x-ray production process the photons are created at a broad spectrum of energies. The term that best describes this type of emission spectrum is: | Heterogeneous |
| In the diagnostic range, the majority of the x-ray photons produced during the x-ray production process are termed: | Bremsstrahlung radiation |
| The amount of filtration and the kilovoltage peak used with a heterogeneous beam are the two main factors that will effect the: | Penetrability and the beam quality |
| The energy of the photons produced during the bremsstrahlung process are dependent upon the: | Energy of the projectile electrons, Atomic # of the target material, The distance between electron and the nucleus |
| The penetrability of an x-ray photon is not effected by | Mass of the photon |
| T/F The atomic # of the material in the target of the x-ray tube will have a significant effect on the energies produced during characteristic x-ray production proess | True |
| The frequency of a diagnostic x-ray photon is directly proportional to | the quality of the beam, The penetrability of the beam, The ionization potential of the beam |
| The efficiency of x-ray production can be calculated with the formula | E= K x Z x KVP |
| The majority of x-rays produced in an x-ray tube are the result of | A rapid deceleration of the projectile electrons as they pass through the target material |
| During a normal radiographic exposure using 100 KVp, bremsstrahlung radiation account for about | 75% of the beam |
| In the diagnostic energy region, approximately what % of electron stream energy is converted into x-rays? | .2% |
| The loss of energy by a projectile electron as it passes by a tungsten nucleus in the anode results in a photon being produced by an event termed? | Bremsstrahlung radiation |
| When the stream of fast- moving electrons interacts with the target of the anode, x-rays are generated by two different processes called: | Leakage and scattered radiation |
Created by:
wilson86