rad exposures
section 1
section 2
section 3
section 4
100
Which of the following is the most likely cause of the change in the emission spectrum represented by the purple line?
increase in kVp
added filtration
single phase to three phase
increase of mA
increase in mA
(Increases in mA increase the quantity of radiation)
100
To keep the electrons together, the focusing cup
has a negative charge.
has a positive charge.
physically surrounds the electron cloud.
physically surrounds the electron cloud and has a negative charge.
physically surrounds the electron cloud and has a negative charge.
100
By regulation, x-ray tube leakage radiation can be no more than
100 R per hour at a distance of one meter.
100 R per minute at a distance of one meter.
100 mR per hour at a distance of one meter.
100 mR per minute at a distance of one meter.
100 mR per hour at a distance of one meter.
100
When the exposure switch at the operating console is first depressed:
high voltage creates a large potential difference between the anode and cathode.
the anode starts rotating.
thermionic emission is achieved.
the anode starts rotating and thermionic emission is achieved.
the anode starts rotating and thermionic emission is achieved.
100
The area of the envelope where x-rays should exit the tube is the
target door.
target window.
x-ray trap.
x-ray gate.
target window
200
Which of the following is the most likely cause of the change in the change of the emission spectrum represented by the purple line?
increase in kVp
added filtration
single phase to three phase
increase in mA
increase in kVp
200
Heat from x-ray production is removed through conduction by the heat traveling from
the tube into the room by cooling fans.
the tube to heat tolerant materials.
the tube to the oil bath.
none of these.
the tube to heat tolerant materials.
200
One of the reasons that molybdenum is used in rotating anodes is because it is
light but strong.
heavy but strong.
dense but strong.
an excellent conductor.
light but strong
200
The melting point of tungsten is
400 °C.
1400 °C.
2400 °C.
3400 °C.
3400 °C.
200
After lengthy exposures, the x-ray tube on a mobile fluoroscopic unit may
become very hot.
produce large electric shocks.
exceed leakage radiation limits.
none of these
becomes very hot
300
What is the most likely cause of the change in the emission spectrum represented by the green line?
increase in mA
increase in kVp
added filtration
single phase to three phase
added filtration
300
Pitting of the anode is the result of
very long exposure times.
high exposures.
failure to warm up the tube.
all of these.
high exposures
300
The atomic number of tungsten is
14.
34.
74.
104.
74
300
Molybdenum
is an excellent conductor of electricity.
is a poor conductor of electricity.
is an excellent thermal conductor.
is a poor thermal conductor.
is a poor thermal conductor.
300
The target window is usually approximately
1 mm2.
5 mm2.
1 cm2.
5 cm2.
5 cm2
400
K shell - 69.5 keV
L shell - 12.1 keV
M shell - 2.82 keV
N shell - 0.6 keV
O shell - 0.08 keV
What is the energy of an x-ray photon produced when an M-shell electron fills an L-shell vacancy?
9.28 keV
400
The focusing cup is made of
tungsten.
nickel.
thorium.
molybdenum.
nickel
400
The stationary anode includes an area of ___________ embedded in a copper rod.
copper
molybdenum
tungsten
glass
tungsten
400
The protective tube housing helps to
keep the tube cool.
prevent electrical shocks to the radiographer.
limit leakage radiation.
provide solid, stable mechanical support.
all of these.
all of these
400
Sun-tanning" in glass envelopes is caused by
the color the tube gets as it loses its resistance to heat over time.
oil leaking out of the protective housing.
the breaking of the glass envelope into small pieces of glass.
the vaporized tungsten from filament deposits that coats the inside of the glass
the vaporized tungsten from filament deposits that coats the inside of the glass.
500
K shell - 69.5 keV
L shell - 12.1 keV
M shell - 2.82 keV
N shell - 0.6 keV
O shell - 0.08 keV
What is the energy of an x-ray photon produced when an O-shell electron fills an L-shell vacancy?
12.02 keV
12.1 - 0.8 = 12.02 (difference in binding energies between the shells)
500
Each cathode filament is approximately
1-3 mm long.
5-6 mm long.
7-15 mm long.
20-35 mm long.
7-15 mm long
500
Which of the following helps to keep the x-ray tube cool on the inside of the protective housing?
Cooling fans
Oil bath
Target window
Cooling fans and an oil bath
cooling fans and an oil bath
500
The stationary anode includes an area of tungsten embedded in
a copper rod.
a tungsten rod.
a molybdenum disc.
a copper disc
a copper rod
500
X-ray tubes with a stationary anode design may be found today
in small x-ray departments.
in medical areas that only need large x-ray exposures.
in medical areas that only need small x-ray exposures.
in medical areas that only image the head and teeth.
in medical areas that only need small x-ray exposures.