Imaging Final Flashcards

What are classified as nucleons?

neutrons and protons

In what shell do the electrons have the greatest binding energy?


As the atomic number of an element gets larger..

the atomic weight, number of nucleons and number of electrons increase.

How do you calculate the number of neutrons in the nucleus from the A
and Z values?


What is the atomic number of an atom with 3 protons, 5 neutrons and 5 electrons?


Which of the subatomic particles has the least mass?


What electrical charge do stable atoms have?


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

protons and electrons

What fundamental particle had and atomic mass number of 0?


Atomic mass number is measure by?

Sum of protons and neutrons

What does it mean when an atom is considered inert?

It has eight electrons in its outer shell.

Atoms in each period of the periodic table of elements have the same
number of:

electron shells

Frequency is determined by?

the number of waves in 1 second

Frequency increases as..

Wavelength shortens

What does frequency times the wavelength equal?


What is the SI unit for frequency?


The height of the wave is called the


The measurement from the top of one wave to the top of the next is called?


An isotope of boron had 5 protons and 6 neutrons, therefore the
atomic number of boron is?


What is the range of wavelengths called that include x-rays,
radio-waves and visible light?

Electromagnetic spectrum

The longer the wavelength..

The lower the frequency

The amount of energy carried in a wave increases as the frequency..


What is the term that refers to the principles of nonmoving electric fields?


Electric flow is the movement of..


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


Electrification that occurs when one object is rubbed against another is?


What is the term for the principles of electric charge in motion?


Potential energy is..

The ability to do work

The difference in electric charge between two points is measured in:


The SI unit for electrons flowing per second is:


What is the SI unit for electric power?


Power in watts equals amperes times:


What is the pathway of and electric current called?

Electric circuit

As resistance increases, current in an electric circuit:


What is the SI unit for resistance?


Current that reverses direction in a circuit many times per second is called:

Alternating current

Which of the following energy conversions takes place in the x-ray machine?

Electrical to radiant

EMF is measured in units of:


A negative charge is attracted to a:

Positive charge

What is considered a good conductor?


The process of electrical fields acting on one another without
physically coming together is:


How many valence electrons would an element have to be considered the
best conductor?


Use Inverse Square Law
A radiographer makes an exposure using a 40" SID. The
intensity at this distance is measured at 5R. The same exposure is
made at 45" SID, what is the radiation intensity at the new distance?

3.95 R

Number of protons in an atom?

Atomic Number

It has shape, form and occupies space?


The force an object exerts under the influence of gravity?


The smallest particle of and element that still posses the
characteristics of that element?


Increase in value the closer the electron is to the nucleus?

Binding energy

Related to the number of electrons in the outermost shell of an atom?


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


Quality of matter contained in an object and remains unchanged
whether the matter of the object is on earth or on the moon.


Force X Distance =


What originate in the decay of a radioactive atom?

Gama rays

Where do the charges reside on the conductor?

External surface

As the length of the conductor increases, what also increases?


What are the only charges that move along a solid conductor?


What makes copper a good conductor?

1 valence electron and 4 electron shells (high binding energy)

Magnetic domains are:

Aligned atoms that produce a magnetic field.

A permanent magnet placed within a coil is called a:


Moving wire through a magnetic field induces:

A current

What is the process called when the current in one coil produces a
current in another coil when the coils are not in direct contact with
one another?

Mutual induction

The magnetic field created by a single electron spinning is called a:


What occurs as the poles of a magnet are stretched farther apart?

The magnet gets weaker

What does a transformer need to operate?

Alternating current

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:

Both directions

What charge does the filament in a vacuum tube have?


What is the positive side of the rectifier tube called?


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


What is produced by a full wave rectification?

Pulsating direct current

Diamagnetic materials are:

Weakly repelled by a magnetic field

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

A changing magnetic field is present

An induction motor is used in an x-ray machine to:

Rotate the anode

A transformer changes electric:


What does a rectifier convert?

AC to DC

What is thermionic emission?

Electron emission from a heated source

How many diodes are used for full wave rectification?


What wave rectified signal is produced by a single diode in a circuit
having an AC power source?

Half wave

Where in the x-ray circuit is the rectifier located?

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

Which line current permits the potential difference to drop to zero
with every change in the direction of current flow?

Single phase power

What part of the x-ray circuit supplies the cathode with power?

Filament circuit

What timer operates from a simple motor that is turning at the same
rate as the generator?

Synchronous timer

What device in the x-ray circuit controls the kVp?


Single phase generators with full wave rectification produce a
voltage ripple of:

2 pulses per Hz

What happens to the tube mA during an exposure using a falling load generator?


Which device in the x-ray circuit controls the mA?

Filament transformer

An electric generator converts _____ energy into _____ energy.

Mechanical, Electrical

What is the unit for magnetic flux density?


Which component of the x-ray equipment requires a step down transformer?

Filament circuit

Wye, star and delta are all types of:

Three phase connections

What is used as the main target material in mammography?


What is the thickness of the absorbing material necessary to reduce
the x-ray intensity to half its original value?

Half-value layer

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

Low energy

What is the diagnostic tube filtration from the composition of the
x-ray tube with an equivalency of about .5-1.0 mm Al?

Inherent filtration

Total filtration can be found by calculating the sum of what?

Added and inherent

What is the charge of the focussing cup?


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


A phenomenon in which the electrons negative charges begin to oppose
the emission of additional electrons at the filament is called:

Space charge effect

99% of the total kinetic energy is converted to what?


Atomic mass number is measured by the number of:

Sum of protons and neutrons

Atoms in each period of the periodic table have the same number of what?

Electron shells

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


The interaction in which an electron and a positron appear when a
photon disappears is called:

Pair production

When are characteristic or secondary photons emitted by an atom?

After a photoelectric interaction

What is known as the difference in densities on an image?


What unit of measurement refers to the measure of intensity of x-ray radiation?


In compton scattering an x-ray photon:

Is diverted by hitting an electron

What is the formula for determining the field size when using an
aperture diaphragm?

(SID X diameter of the diaphragm) / distance from the focal spot to diaphragm

What is attenuation?

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

What is the atomic # of bone?