Distance
If the distance from an X-ray source is ________, then the intensity of the beam is reduced by a factor of 4.
doubled/increased by a factor of 2
The maximum energy level that an individual photon can have is represented by:
kilovoltage peak (kVp)
Distance is _________ proportional to the intensity of a beam.
inversely
What represents Z?
Number of protons in the nucleus.
To double optical density, the technologist must double:
mAs
SOD + OID = _____
SID
68,000 V = ______ kVp
68 kVp
What math equation represents the quantity of photons in a beam?
milliamperes (mA) x time (s) = mAs
If an atom has 34 protons and 17 neutrons, what is its atomic number?
34
Increasing kVp has what effect on patient dose and receptor dose?
Patient dose: decrease; Receptor dose: increase
A patient is positioned at a 40" SID for 2 exposures. Image 1 is taken with a 37-inch SOD and Image 2 is taken at 39-inch SOD.
A: Which image will have less distortion?
B: Which will have higher contrast?
A. Image 2
B. Image 1
In a three-phase, 12-pulse X-ray system, how much of the incoming energy is used to produce X-rays?
~96% of the energy (voltage ripple ~4%)
If distance is doubled from 3 feet to 6 feet, what would the intensity become if the original intensity was 24 mGy?
6 mGy
The maximum number of electrons in the N shell are:
32 electrons
If a technologist wants to increase contrast but maintain density after using 83 kVp and 14 mAs, what new technique could accomplish this?
73 kVp and 28 mAs using the 15% rule
What technique should the technologist use to maintain exposure if the 1st radiograph was completed at 40" SID using 65 kVp and 8 mAs, but the 2nd image was taken at 60" SID?
65 kVp and 18 mAs
A primary coil of a step-up transformer has 175 turns and utilizes 400 volts and 15 Amps. What is the measured potential difference on the secondary coil if it increases to 450 turns?
~1,030 Volts (1,028.57 Volts)
A primary coil of a step-up transformer has 175 turns and utilizes 400 volts and 15 Amps. What is the measured current on the secondary coil if it increases to 450 turns?
~6 Amps (5.83 Amps)
An aluminum atom has 14 neutrons and an atomic number of 13. How many protons does it have? What is its atomic mass unit?
13; 27
Decrease the mAs to 43 (half) or decrease the kVp by 15% to 85 kVp and keep the mAs constant.
What distance must the technologist stand to reduce their dose to 3.4 mR if they are currently receiving 9.7 mR standing 2 feet from the source?
~3.4 feet (3.378 feet)
How many turns are on the secondary side of a mutual transformer if the potential difference is measured as 250 volts with 170 turns, and the primary side measures 575 volts? What type of transformer is it?
391 turns; Step-down transformer
How many turns are on the primary side of a mutual transformer if the current measured on the secondary side is 5.4 Amps with 250 turns, and the primary side measures 3.2 Amps? What type of transformer is it?
~422 turns (421.87 turns); Step-down transformer
An incoming electron has 87 keV. Upon changing direction, it loses 16 keV. What type of X-ray did this interaction produce, and what is the keV of that photon?
Bremsstrahlung; 16 keV
How many heat units are produced after 1 exposure is taken using 60 kVp, 100 mA, 0.01 seconds on a three-phase, 12-pulse system and a 2nd exposure on the same system using 65 kVp, 300 mA, and 40 milliseconds?
1,184.4 HU