Final Notecards Flashcards

To calculate the number of neutrons in the nucleus from A and Z values:


What is the atomic number of an atom with three protons, five
neutrons, and five electrons?

3 (number of protons)

In an electrically stable atom there are an equal number of?

protons and electrons

What is the SI unit for frequency?


An isotope of Boron has 5 protons and 6 neutrons. The atomic number
of boron is which of the following...11, 10, 6, 5?


What is created when electrons are bumped into or out of electron shells?


What is the pathway of an electric current called?

Electric circuit

Smallest particle of a compound that still posses the characteristics
of the compound


T/F: x-rays can be focused by a lens?


T/F: as the length of conductor increases, resistance increases?


A semiconductor rectifier is made by putting together n-type and
p-type semiconductors. Joined together, what are these semiconductors called?


In ferromagnetic material:

a majority of the magnetic dipoles are lying in the same direction
AND greatly susceptible to magnetic induction

Given a closed loop of wire with no electron flow, an electric
current can be induced if:

a changing magnetic field is present

Electrons flow:

from cathode to anode

Thermionic emission refers to:

electron emission from a heated source

At what point in the x-ray circuit is the rectification circuit located?

between the step-up transformer and the x-ray tube

The timer that operates from a simple motor that is turning at the
same rate as the generator is the:

synchronous timer

Wye, star and delta are all examples of:

three phase connections

When a projectile electron from the filament enters a target atom and
interacts with the nuclear force field it will:

decrease in velocity

Diagnostic filtration is principally employed to reduce the _____
photons from reaching the patient.

low energy AND short wavelength

What element is used to conduct heat away from the anode target?


The intensity of the heel effect depends on:

the angle of the target AND the distance between the film and x-ray
tube AND the size of the radiographic film used

The amount of energy carried in a wave increases as the:

frequency increases

Which of the following is true when an x-ray machine is set at 100kVp?

the most energetic x-ray has an energy of 100keV

If motion is a problem, and 50mAs is needed, which of the following
mA stations would best be selected?

400mA (because want high mA with short exposure)

The amount of darkening seen on any radiograph is termed:


The greater the number of photons reaching the IR, the:

greater the density

An increase in image density can result from an increase in:

kVp AND mAs

If you halved the time of exposure, how much would you change the mA
to obtain the same density on the radiograph?

double the mA

If the incident and scattered photon have the same wavelength, the
scattering process is said to be:


The probability of photoelectric effect ____ when the atomic number
of matter ____.

increases, increases

The probability of photoelectric effect _____ when photon energy increases.


How does increasing kVp by 15% affect density?

doubles density

Increasing SID does what to density if all other factors are unchanged?

decreases density

What is the result of scattered radiation reaching the film?

fog AND more density AND less contrast

Of the three characteristics of x-rays which ones contribution is
least beneficial to the formation of an x-ray image?


What does the kVp setting control?

the kinetic energy of projectile electrons

To reduce film fogging, the Compton effect should be:


What will happen if the kVp setting remains the same and the mA
setting is increased?

the electrons will have the same energy level

The probability of photoelectric interactions is higher with:

low energy x-rays

As the energy level of an incident x-ray increases, the probability
of Compton scattering:


If the kVp setting is too high:

too much penetration will occur

Which of the following, if decreased, would cause a decrease in ESE?


True/False: If the kVp is changed from 50 to 100 with no change in
mAs, the resultant density will be doubled?


The pairs of shutters in collimators can be controlled independently
to create which of the following:

different field sizes

The light inside the collimator is used to do what?

help position the patient

Which of the following is true of a positive beam limitation device?

it required all new fixed radiographic equipment, it ensures the
field size is never larger than the image receptor, it works
automatically to determine CR cassette size used

Attenuation is defined as:

reduction in the total number of x-ray photons reaching the film

The higher the atomic number of the material being irradiated, the
____ the percentage of attenuation?


True/False: Air absorbs fewer photons than fat.


Photons passing through a material with a low atomic number will
produce ____ radiographic density.


True/False: Fat has more tissue density than muscle.


Which of the following lists the basic substances of the body in the
correct order of more dense to less dense?

bone, muscle, fat, air

What is subject density?

will be altered by changes in the amount or type of tissue being irradiated

What is subject detail?

dependant on the position of structures within the body and the
body's placement in relationship to the primary factor that
affects this is distance

Which of the following is a reason that anodes are usually made from tungston?

has high melting point

Which of the following interactions will create the x-ray with the
lowest keV?

an electron passes relatively far away from the nucleus of an atom

The use of diagnostic x-ray filtration has the following effects:

increased beam quality, decreased skin dose, and decrease the number
of long wavelength photons

Leakage radiation refers to:

x-rays that escape through the protective housing

Which of the following is true of all electromagnetic radiation?

carry their energy in waves, have varying levels of energy, and they
travel at the speed of light

The transformer law states that there is a direct proportion between
the ratio of wire turns on a coil and the ratio of:


A rectifier works by allowing electrons to flow through it in:

one direction

Diamagnetic materals are:

repelled by a magnetic field

Thermionic emission refers to:

electron emission from a heated source

A single diode in a circuit having an AC power source produces a ____
wave rectified singal.


The use of diagnostic x-ray filtration has the following effects:

increased beam quality, decreased skin dose, and decrease in the
number of long wavelength photons

The shapeness of an x-ray image can be increased by:

decreasing the size of the focal spot