Ch. 4 Physics Flashcards
Has no mass & is invisible
Travel in straight lines at the speed of light
Can ionize matter
Produce biological change in tissue
Penetration depends on atomic # & tissue thickness
Characteristics of x-rays
Frequency x wavelength
Rate at which x-rays travel
Velocity
A neutral atom gains / loses an electronic and produces an electric charge
Gain: neg
Lose: pos.
Ionization
Matter and energy can not be created or destroyed but can change form
Matter: occupies space and has shape
Mass: QUANTITY “weight” of matter
Law of conservation
The difference in electrical charge between 2 points in a circuit
- force /speed of electron flow= QUANTITY (KVP)
Potential Difference
In/decrease voltage by fixed amount
Transformer
Number of secondary turns vs primary turns
(First number always = secondary side)
Transformer ratio
Converts AC to DC by the use of transformers
Rectification
Allows electrons to flow in one direction
Diode
Magnets produce electricity; electricity produces magnetism
- primary circuit: connection to pwr supply
- secondary circuit: carries induced current
- induced current: current generated due to the mechanical motion of metal in a magnetic field
Electromagnetic induction
Resistance: hinders flow (ohms)
Current: QUANTITY of electrons (mAs)
Potential diffedence: QUALITY of electrons (kVp)
Electric units in x-rays
Potential energy = tube
Thermal energy= 99% heat
Electric energy = high &low voltage
Electromagnetic enery= mainly used
Energy type used in x-ray production
Tungsten (W)
Atomic #: 74
Mass #: 184
Binding energy: 69 keV
Element used in x-ray production
Kvp & mAs are ___ while flowing through a transformer
Inversely proportional
Voltage in/decrease is ____ to the number of turns in each turn
Directly proportional
