Question | Answer |
what is matter | anything that occupies space and has mass |
all matter is compose of what | all matter is composed of atoms |
how is matter measured | measured in kilograms |
what is mass | the quantity of matter in a physical object |
how is mass measured | measured in kilograms |
what is energy | the ability to do work |
how is energy measured | measured in joules |
what is potential energy | stored energy |
what is kinetic energy | energy in motion |
what is electrical energy | result from the movement of electrons |
what is the law of conservation of matter | matter cannot be created or destroyed |
what is the law of conservation of energy | energy cannot be created or destroyed |
(radiology)electrical energy produces electromagnetic energy, which is then coverted into what | chemical energy |
what is ionization | radiation that is capable of removing an orbital electron from an atom with which it interacts. |
what is the two kinds of radiation | natural and man-made |
what is the similar with both radiations | both are ionizing radiation |
what is the largest natural radiation | radon is the largest source of natural radiation |
what is the largest source of man-made radiation | diagnostic x-rays are the largest source of man-made radiation |
what are some natural forms of radiation | cosmic,terrestrial,deposited radionuclides |
what are some man-made forms of radiation | industry,nuclear medicine,medicine |
how did William Roentgen discover x-rays | with a crookes tube accidentally-nov.8,1895 |
the glass plate was covered with what when it started to glow | barium platinocyanide |
who was the 1st to get x-rayed and when | Bertha Roentgen(Roentgen'swife) 1896 |
who was the 1st to demonstrate intensifying screen | Michael Pupin-1896 |
who invented the flouroscope and when | Thomas Edison-1898 |
when was it 1st realized that radiation causes bilogic changes | 1898 |
when was Roentgen awarded the nobel prize | 1901 |
when was the 1st recorded fatality due to radiation,and who was it | Thomas Edison assistant clarence Daily-1904 |
when was the coolidge hot filament discovered | 1913 |
when was the Potter-Bucky introduced | 1921 |
what does ALARA stands for | as low as reasonably achievable |
what are the basic concepts of radiation protection | filtration,collimation,intensifying screens,gonadal shielding,protective barriers |
what are the properties of x-rays | highly penetrating invisible form of electromagnetic radiation,electrically neutral,not affected by other fields,polyenergetic,releases small amounts of heat when passing through matter,travels in straight lines,travels at the speed of light 3x10 8th,can |
what is a photon | the smallest quantity of electromagnetic radiation,just as an atom is the smallest part of an element. |
what is another name for photon | quantum |
photons are constantly changing in variation called what | sine waves |
what are the properties of a photon | amplitude,frequency,wavelength,velocity |
what is amplitude | one half the height of wave from crest to valley |
what is frequency(f) | number of wavelengths passing a point per second |
how is frequency measured | measured in hertz |
what is wavelength | the distance from one crest to another crest or from valley to another valley |
velocity travels at what speed | 3x10 8th(speed of light) |
which is the only property which is constant | velocity |
wavelength and frequency are what | inversely proportional-as the wavelength increases,energy decreases |
ELECTRICITY | #2 |
what is electricity | defined as the flow of electrons |
unlike charges attract,like charges repel,electrons are--,protons are-- | negative,positive |
what is the smallest unit of an electrical charge | electrons |
electrical potential is measured in | volts |
electrical potential is known as | potential difference,electromotive force |
how is electrical current measured | measured in amperes(A) |
what does the ampere measures | measures the number of electrons flowing in the electric circuit |
how is electric resistance measured | electric resistance is measured in ohms |
how does electrons flow in alternating current(AC) | electrons flow back and forth on a conductor |
how does electrons flow in direct current(DC) | electrons flow in one direction along the conductor |
in United States,electrical circuits operate in what | 60-cycle alternating current.One cycle has two pulses of current-one negative-one positive |
in what ways can you control electric current | conductor,insulator,resistor |
what is a conductor | any substance in which electrons can flo through easily-cooper,water |
what is a insulator | any substance that doe not allow electron flow,confines electrons to the conductor-rubber |
what is a resistor | any substance that inhibits the flow of electrons |
what is a electric circuit | when the conductor is made into a closed path |
what are the two kinds of circuits | series and parallel |
what is a series circuit | all circuit elements are connected in a line along the same conductor(old christmas lights) |
what is a parallel circuit | connected at their ends rather than in a line(new christmas lights) |
how is electric power measured | measured in watts |
how is a magnetic field strenght measured | measured in tesla(T) |
what is diamagnetic | these materials are unaffected when brought into a magnetic field(wood,glass and plastic) |
what is ferromagnetic | strongly affected by a magnetic(iron,cobalt and nickel) |
what is paramagnetic | in between (MRI contrast,tungsten) |
what is electromagnetism | uses electricity and magnets to induce an electric current |
what is a solenoid | a coil of wire through which electric current flows |
what is an electromagnet | a current-carrying coil of wire wrapped around an iron core,which intensifies the magnetic field |
what is Faraday's law | states that an electric current is induced to flow in a circuit if that circuit is in a moving magnetic field |
what is self-induction | induction of a opposing voltage in a single coil by its own changing magnetic field |
what is mutual induction | the generation of an alternating current in a secondary coil by supplying an alternating current to the primary coil |
what is a electric generator | a coil of wire is rotated in a magnetic field,causing a current to be generated in the wire,used to converted mechanical energy int electrical energy |
what is a electric motor | in an x-ray tube,an induction motor is used-an induction motor powers the rotating anode of an x-ray tube |
what is a transformer | a electrical device operating on the principle of mutual induction to change the magnitude of current & voltage |
what is a step-up transformer | if there is more coil windings on the secondary side of the core than on the first-voltage increases |
what is a step-down transformer | if there are less coil windings on the secondary side than the primary side-voltage decreases |
what is the most efficient type of transformer | is the shell-type transformer |
what is the turns ratio | the number of turns in the primary coil compared with the number of wire turns in the secondary coil |
autotransformer is known as | variable transformer |
what is an autotransformer | single coil of wire with an iron core,used to select kV,operates on the principle of self-induction, 220 volts coming from wall autotransformer preps kv for high voltage side |
what are the 3 main parts to an imaging system | tube,operating console, high voltage generator |
what are the parts on the primary low-voltage circuit | line voltage compensator,autoformer,ma selector,kv meter, timer circuit |
what is the line voltage compensator | compensates for variation in voltage coming from power company |
what is the autotransformer | kv selector,operates on principle of self induction,has a single winding & supplies precise voltage to the filament circuit & to the high voltage circuit of the imaging system |
what is the mA selector | connected to filament circuit |
what is the kV | shows kV selected |
what is the timer circuit | controls lenght of exposure |
what are the parts to the secondary high voltage circuit | step-up transformer,mA meter,rectifier |
what is the step-up transformer | steps up voltage and steps down amperage,operates on principle of mutual induction,more turns on secondary side |
what is the mA meter | shows mA selected-measures tube current |
what is the rectifier | converts AC to DC |
how does the step down transformer steps down voltage and steps up current | in responses to the use of rheostats selected by the radiographer at the mA stations,operates on mutual induction |
what does the rectification do | converts AC to DC-the x-ray circuit requires AC while the tube cannot take AC must be converted to DC |
three phase generators-what is the voltage | 3 phase-6 pulse 13-25% voltage ripple3 phase-12 pulse 4-10% voltage ripplehigh frequency generator<1% voltage ripple |