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Rad Phys Final
rad phys final
Question | Answer |
---|---|
energy of position | potential energy |
energy of motion | kinetic energy |
elements | simple substance |
compound | complex substance |
smallest particle of a compound possessing characteristics of the compound | molecule |
the smallest component of an element having the chemical properties of the element | atom |
positive charge | proton |
neutral charge | neutron |
negative charge | electron |
contains the protons and neutrons | nucleus |
orbit the nucleus | electrons |
one of two or more atoms with the same atomic number but with different numbers of neutrons. they are unstable | isotopes |
like charges repel & unlike charges attract | law of electrostatics |
negative charge | cathode |
positive charge | anode |
when the filament is heated, electrons are released | thermionic emission |
the intensity of a radiation field is inversely proportional to the square of the distance from the source. | inverse square law |
electric pressure | volts |
amount | amps |
resistance | ohms |
#18. two bodies of same charge | repel |
#11. the atomic number (z number) is equal to | protons |
#8. particles around nucleus | electrons |
power loss formula | PL= I^2R |
power formula | P= VI |
all electrons spin in the same direction | magnetic field |
converts electrical energy to mechanical energy | motor |
converts mechanic energy to electrical energy | generator |
commutator rings | DC motors |
slip rings | AC motors |
x-ray tubes use _________ | DC |
connected to the mA selector | rheostat |
connected to the kV selector | autotransformer |
connected to the time selector | timing circuit |
changes AC to DC | rectifier |
sends charge to x-ray tube | capacitor |
takes low voltage from autotransformer and steps it up for the tube | step-up transformer |
reduces voltage to the filament of the x-ray tube (increases amperage) | step-down transformer |
eddy, copper loss & hysterisis | transformer powerloss |
x-rays can be focused by a lens | false |
x-ray tubes produce beams that are homogenous and monoenergetic | false |
x-rays produce minute amounts of heat when passing through matter | true |
x-rays are negatively charged like electrons | false |
x-rays will ionize atoms by removing electrons from their orbits | true |
x-rays do not affect photographic film | false |
x-rays have a dualistic nature; behaving like particles and also like waves | true |
the direction of a flow of electrons can be affected by a magnetic or electric field | false |
the direction of a flow of x-rays can be affected by a magnetic or electric field | false |
#31. electrical ----> mechanical | motor |
#32. electrical current | AC |
#33. uses 10 volts and 50 amps | *use power formula* |
#45. speed of light/x-rays | frequency of radiation multiplied by |
a unit of exposure in the air equal to creation of 2.08 x 10^9 ion pairs per cc of air | roentgen |
unit of dose equivalence | rem |
describes the quantity of radioactive material | curie |
unit of absorbed dose | rad |
produces a charge of 2.58 x 10 ^-4 coulombs per kilogram | roentgen |
SI equivalent is the gray | rad |
SI equivalent is the sievert | rem |
determined by rads x quality factor | rem |
SI equivalent is the becquerel | curie |
mini solar system | bohr |
advising agency | NRC |
kV x mA x t x phase= | heat units |
use p-n junction semiconductors | solid state rectifier |
process of changing AC to DC | rectification |
V = IR (V= volts of potential diff, I= amps of current, R= ohms of resistance) | Ohm's law |
motor in an x-ray tube | induction motor |
actual focal spot always larger than effective focal spot | line focus principle |
#62. single phase at 30 kV, 500 mA, and 1/30th of a second. | *HU formula* |
#68. what timer is used in a single phase machine? | counting sine waves |
#75. HU chart | is exposure safe |
incident electron interacts with electrostatic force field of nucleus | brems interactions |
incident electron interacts with k-shell electron | characteristic interaction |
in a DNA macromolecule, the sequence of _______ determines the characteristics of every living thing | nitrogenous organic bases |
radiation induced chromosome damage may be evaluated during ________ | metaphase |
primary energy source of cells | carbohydrates |
provides info controlling cell growth and metabolism | nucleic acid |
produces antibodies | lymphocytes |
protein synthesis occurs here | ribosomes |
somatic cells divide through | mitosis |
during mitosis, two new nuclei form during _______ | telophase |
process of reducing cell division | meiosis |
free radicals behave as an extremely reactive single entity as a result of | unpaired electrons |
cellular garbage disposal | lysosomes |
cancer and genetic defects are examples of | stochastic effects |
#130. | A |
#135. more damage | B (high LET) |
#110. Which are by-products of PE absorption? | D (characteristic) |
the linear, nonthreshold curve implies that biologic response is | directly proportion to the dose |
stochastic effect is the same as | probabilistic |
no threshold | stochastic |
threshold | deterministic |
nonstochastic = deterministic = threshold | early somatic effects |
stochastic = probabilistic = nonthreshold | late somatic effects |
radiosensitivity of cells is directly proportional to reproductive activity and inversely proportional to their degree of differentiation | law of B & T |
50% of the population will be dead within 30 days | LD 50/30 |
the amount of energy delivered per unit track by radiation | LET |
oxygen concentration will increase the likelihood of radiation damage | OER |
high LET radiation is likely to cause _____ damage than low LET radiation | more |
example of high LET radiation | alpha particle |
a filter operates via | PE interactions |