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
What types of generators are used in x-ray
High frequency
There are more turns on the secondary side
Step up transformer
There are more turns on the primary side
Step down transformer
Shell closest to the nucleus that contains 2 electrons
K-shell
