Chapter 4,5,6 Study Questions Flashcards
Which of the following would be considered a basic form of matter?
Solid and Liquid
The quantity of matter that makes up any physical object is called the:
Mass
Which of the following is located in an orbit around the nucleus of an atom?
Electron
Which of the following has a negative (-) electrical charge?
Electron
Which of the following are considered fundamental particles of atoms
Neutrons and Photons
When a neutral atom gains or loses an electron, the atom is said to be:
ionized
Mechanical energy can be classified as either kinetic energy or
Potential Energy
X-rays consist of
Electromagnetic Energy
X-rays with greater energy have a shorter____and or more penetrating.
Wavelength
Of the following types of electromagnet magnetic energy, which has the shortest wavelength?
Diagnostic Rays
Which of the following are accurate statements regarding the characteristics of X-rays?
They are highly penetrating and invisible and They travel in straight lines at the speed of light
The smallest possible unit of electromagnetic energy is the
Photon
The term for continuous path for the flow of electrical charges from the power source through one or more electrical devices and back to the source is:
Electrical Circuit
The common unit of measure for the potential differences across an X-ray tube is:
Volt
The purpose of a transformer is to:
Increase or decrease voltage
Which electron shell in the atom is most important for production of X-rays
K Shell
Electrons are held in place around the nucleus of the atom by an
Binding Energy
Atom gains or loses an electron it is called:
Ion
Process of converting AC to DC is called
Rectification
One of the most important elements in radiology that is used to create X-rays is
Tungsten
X-rays cause ionization in the body.This is a negative effect on the body:
True
When a step-up transformer increases voltage from the primary side to the secondary side of the transformer. Amperage is increasing.
False
If a transformer has 100 turns on the primary side and 25 turns on the secondary side, it is a step down transformer:
True
A transformer with a 500:1 ratio would be a step down transformer:
True
X-rays with greater energy have a lower frequency:
False
X-rays can cause cancer
True
Roentgen discovered x-rays while working with an _____tube.
Crookes
An “electron cloud” surrounding the filament of the cathode is referred to as a:
Space charge
Free electrons for X-ray production come from the:
Filament
The creation of the space charge in the X-ray tube produces:
Thermionic emission
The majority of photons and the X-ray beam are created by which process?
Bremsstrahlung interactions
More than 99% of the energy of the electron stream is converted into:
Heat
The high-speed rotation, 10,000 RPM of the anode enables:
Greater dissipation of heat from high technical factors
The degree of angulation of the X-ray tube target will determine the:
Shape of the x-ray beam
A dual focused X-ray tube has:
Two filaments and two focal spot sizes
The anode heel effect is a phenomenon of X-ray production that results in:
Uneven distribution of radiation within the x-ray field
To take advantage of the anode heel effect when making a radiograph of the femur in recumbent anterior posterior projection on a 14x17 inch image receptor at a 40 inch source image receptor distance SID. The patient should be placed so that the:
Head is toward the cathode end of the tube
The penetrating power of the X-ray beam is controlled by varying the:
Peak kilovoltage (kVp)
The rate of current flow across the X-ray tube is measured in
mA
Doubling the mA will result in:
Increased patient dose, twice as many photons in the x-ray beam
The unit used to indicate the total quantity of X-ray exposure is:
Milliampere-seconds (mAs)
An X-ray exposure is made using the following factors: 200 MA, 0.02 seconds, 70 KVP, 40 inches SID. The value of the mAs for this exposure is:
200 mA x 0.02 seconds = 4
The device for removing long wavelength radiation for the primary X-ray beam is the:
Filter
X-ray equipment capable of producing 70 KVP more is required to have total filtration of at least:
1.5 mm Al equiv
The purpose of rotating the anode of the X-ray tube is to:
Increase the heat capacity of the anode
Image sharpness is determined by the:
Size of the effective focal spot
Above 70 KVP, what percentage of photons is created by the bremsstrahlung process?
85%
The amount of detail seen in the X-ray image is referred to as:
Spatial resolution
All of the following devices are located within the low voltage circuit and control console except the:
Step-up transformer
The auto-transformers primary purpose is to vary the
Voltage
Which transformer is located in the filament circuit?
Step-down transformer
The primary purpose of the filament circuit is to:
Heat the x-ray tube filament for the thermionic emission
A timer that is capable of producing ultra short exposure times is typical of an:
Electronic timer
The primary purpose of a rectifier in a X-ray circuit is to
Change alternating current (AC) into direct current (DC)
The primary purpose of the high voltage circuit is to:
Supply the x-ray tube with voltage high enough to produce x-rays
The advantages of using a high frequency generator instead of a single phase generator include:
Producing X-rays more efficiently.Requiring less exposure time to produce a given amount of exposure.Producing the greatest amount of X-rays for the same exposure technique.
How much can the exposure time be decreased when using three phase X-ray equipment?
40%
Automatic exposure control automatically varies the:
Exposure time
Into the tube rating chart below, what is the maximum exposure time obtainable at 90 KVP and 500 MA?
1/20 sec
Which of the following steps should be used to extend X-ray tube life?
Warm up the anode and do not make repeat exposures near the tube limits.
How many heat units are generated using a high frequency generator at 200 MA, 0.10 second and 85 KVP?
2380 HU’s
For which type of X-ray exposure system can the technical factors be programmed into the system?
Anatomically programmed radiography (APR)
Which transformer is located in the high voltage circuit?
Step-up Transformer
How much higher is the percentage of X-rays produced in a three phase X-ray machine?
40%
In a high frequency X-ray generator, the standard 60 Hz frequency is increased to about:
6000 Hz
The highest power X-ray generator is the:
High-frequency generator
The advantage of full wave rectification is that the exposure time can be cut in half.
True
The lowest power X-ray machine is a three phase machine
False
The shortest exposure times are obtained using high frequency generators
True
The heat unit formula for a three phase X-ray generator is: HU= mA x Time x kVp x 1.35
True
