2025 LRA 222 Final Exam New Latest Version Best
Studying Material with All Questions and 100%
Correct Answer
How many windings does the auto transformer have? ---------- Correct Answer ----------- 1
To produce x-rays, a cloud of electrons are necessary and the cathode must have a strong
positive charge. ----------- Correct Answer ------------ False
Which of the following occurs first in the sequence of events leading to x-ray production? --------
--- Correct Answer ------------ Voltage becomes kilovoltage.
The rate of flow of electrons passing through the x-ray tube during an exposure is -----------
Correct Answer ------------ tube current.
The operating console contains circuits that are ------------ Correct Answer ------------ low voltage
only
Thermionic emission at the filament determines the ______ across the x-ray tube during an
exposure ------------ Correct Answer ------------ Milliamperage (mA)
The auto transformer has ______winding(s) ------------ Correct Answer ------------ 1
A grid reduces the amount of scatter radiation that reaches the patient ------------- Correct Answer
----------- false
Grids absorb almost all of the scatter radiation and allow all of the transmitted photons to pass
through to the IR. ------------- Correct Answer ----------- false
Adding a grid or increasing grid ratio results in an increase in patient dose. ------------- Correct
Answer ----------- true
Should the thickest part or the thinnest part be placed under cathode? ---------- Correct Answer --
--------- Thickest
The target of the rotating anode is usually coated with a _____ alloy ------------ Correct Answer -
---------- Tungsten
Because of the line focus principal, the effective focal spot size decreases with decreasing _____.
------------ Correct Answer ----------- target angle
What is the most common cause of tube failure ------------ Correct Answer ----------- tungsten
vaporization
,What are the three main parts of the x-ray imaging system? ---------- Correct Answer ----------- x-
ray tube, operating console, high voltage generator
True or false? The x-ray beam generated by the circuit with the lowest voltage ripple has the
highest quantity and quality. ---------- Correct Answer ----------- True
What type of generator units do mammography units operate with? ---------- Correct Answer -----
------ High frequency generators
Are long or short exposure times more likely to cause to failure ---------- Correct Answer ---------
-- Long
Localized, potting, or cracking on the anode can be caused by what? ---------- Correct Answer ---
-------- A single excessive exposure
What causes the anode heal effect? ---------- Correct Answer ----------- Xray absorption within
the anode
True or False? As an x-ray to gets older, the inside may become coded with tungstun, and which
can cause arcing in the tube. ---------- Correct Answer ----------- True
Are the stators on the inside or the outside of the glass envelope? ---------- Correct Answer -------
---- Outside
The ___ is the source of radiation in the xray tube ---------- Correct Answer ----------- focal spot
What does the tube rating show? ---------- Correct Answer ----------- Longest exposure time of
xray tube can be energized without overheating
What creates space charge? ---------- Correct Answer ----------- The heating of the filament which
boils off electrons
What is the target of the rotating and usually coated with? ---------- Correct Answer -----------
Tungsten
What is the most common cause for tube failure? ---------- Correct Answer ----------- tungsten
vaporization
High capacity tube rotors revolve at _____ rpm. ---------- Correct Answer ----------- 10,000
How many filaments does a dual focus tube have? ---------- Correct Answer ----------- 2
Is the filament on the positive or negative side of the tube? ---------- Correct Answer -----------
Negative
What is a filament made of? ---------- Correct Answer ----------- Tungsten
, What are the components of the anode? ---------- Correct Answer ----------- stator and rotor
What are the components of the cathode? ---------- Correct Answer ----------- filament and
focusing cup
With the rotating anode the focal spot becomes what? ---------- Correct Answer ----------- Focal
track
Why does the focusing cup keep the electrons together? ---------- Correct Answer -----------
Repelling them into a group bc negative repels negative
What is the stator made of? ---------- Correct Answer ----------- electromagnets
What happens to the tube if you prep the rotor, but do not expose an x-ray often? ----------
Correct Answer ----------- Damage
Where is the main power switch located? ---------- Correct Answer ----------- primary circuit
Where is the primary side of the high voltage transformer found? ---------- Correct Answer -------
---- primary circuit
Where is the timer circuit found? ---------- Correct Answer ----------- primary circuit
Where is the step down transformer found? ---------- Correct Answer ----------- filament circuit
What is the purpose of a line compensator? ---------- Correct Answer ----------- Measures and
stabilizes voltage
What is the purpose of the rectifier? ---------- Correct Answer ----------- Convert AC to DC
What is the purpose of the filament circuit? ---------- Correct Answer ----------- Boils electrons/
thermionic emission
What is the primary purpose of a step down transformer? ---------- Correct Answer -----------
Coverts high voltage to low voltage
To produce x-rays, does a cathode require positive or negative charge? ---------- Correct Answer
----------- Negative
What is tube current? ---------- Correct Answer ----------- Rate of flow of electrons
AEC ---------- Correct Answer ----------- automatic exposure control
What does AEC control? ---------- Correct Answer ----------- the quantity of radiation reaching
the IR
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