ROC 125 EXAM UPDATED QUESTIONS AND ANSWERS
touch detector 5 - CORRECT ANSWER✅✅✅If the _______ ________ encounters a force
approximately ________ pounds in any direction, the reset button on the interface mount lights red and
all Clinac motors are disabled.
5 - CORRECT ANSWER✅✅✅____ pounds of pressure disable the Clinac motors.
photons electrons - CORRECT ANSWER✅✅✅Personal blocks are only used with __________, not
________
12 - CORRECT ANSWER✅✅✅Electrons use _____ mm minimum Cerrobend thickness
63 6.3 - CORRECT ANSWER✅✅✅6x HVL--15mm 5% transmission of _____ mm/ ________cm
minimum
74 7.4 - CORRECT ANSWER✅✅✅18x HVL--17mm 5% transmission of _____ mm/ ________cm
minimum
20 - CORRECT ANSWER✅✅✅Personal blocks must be a minimum of ______ cm from the patient
1.2 - CORRECT ANSWER✅✅✅Electrons use _____ cm minimum Cerrobend thickness
lead - CORRECT ANSWER✅✅✅MeV/2 is the shield thickness in mm of what material?
MeV/2 - CORRECT ANSWER✅✅✅________ is the shield thickness in mm of lead.
Cerrobend - CORRECT ANSWER✅✅✅The melting point of _______ is between 172-175 degrees.
shielding - CORRECT ANSWER✅✅✅Cerrobend is the composition of the alloy used for
______________
, bismuth lead tin cadmium - CORRECT ANSWER✅✅✅Cerrobend is made of 50% __________, 26.7%
___________, 13.3% ____________, and 10% _________
lead cadmium - CORRECT ANSWER✅✅✅What are the two most toxic compounds in Cerrobend?
1/2 - CORRECT ANSWER✅✅✅When treating with electrons, the beam penetration is _______ the
initial energy
1/3 - CORRECT ANSWER✅✅✅80% of the electron beam's energy is at _________ of the initial beam
energy
80% line - CORRECT ANSWER✅✅✅the ________ ____________ is beam energy divided by 3.
horseshoe - CORRECT ANSWER✅✅✅The __________ has to be on in order for an electron cone
beam to be placed (adapter and cone beam)
cone beam - CORRECT ANSWER✅✅✅There are five sizes for the electron ______ _______, which
are:
6x6 (6^2)
10x10 (10^2)
15x15 (15^2)
20x20 (20^2)
25x25 (25^2)
touch detector - CORRECT ANSWER✅✅✅The _______ __________ will stop all movement with the
cones if 5 lbs of pressure is applied.
electron cone beam - CORRECT ANSWER✅✅✅With the _________ ________ ______, never operate
the gantry from outside the room (offers no clearance)
touch detector 5 - CORRECT ANSWER✅✅✅If the _______ ________ encounters a force
approximately ________ pounds in any direction, the reset button on the interface mount lights red and
all Clinac motors are disabled.
5 - CORRECT ANSWER✅✅✅____ pounds of pressure disable the Clinac motors.
photons electrons - CORRECT ANSWER✅✅✅Personal blocks are only used with __________, not
________
12 - CORRECT ANSWER✅✅✅Electrons use _____ mm minimum Cerrobend thickness
63 6.3 - CORRECT ANSWER✅✅✅6x HVL--15mm 5% transmission of _____ mm/ ________cm
minimum
74 7.4 - CORRECT ANSWER✅✅✅18x HVL--17mm 5% transmission of _____ mm/ ________cm
minimum
20 - CORRECT ANSWER✅✅✅Personal blocks must be a minimum of ______ cm from the patient
1.2 - CORRECT ANSWER✅✅✅Electrons use _____ cm minimum Cerrobend thickness
lead - CORRECT ANSWER✅✅✅MeV/2 is the shield thickness in mm of what material?
MeV/2 - CORRECT ANSWER✅✅✅________ is the shield thickness in mm of lead.
Cerrobend - CORRECT ANSWER✅✅✅The melting point of _______ is between 172-175 degrees.
shielding - CORRECT ANSWER✅✅✅Cerrobend is the composition of the alloy used for
______________
, bismuth lead tin cadmium - CORRECT ANSWER✅✅✅Cerrobend is made of 50% __________, 26.7%
___________, 13.3% ____________, and 10% _________
lead cadmium - CORRECT ANSWER✅✅✅What are the two most toxic compounds in Cerrobend?
1/2 - CORRECT ANSWER✅✅✅When treating with electrons, the beam penetration is _______ the
initial energy
1/3 - CORRECT ANSWER✅✅✅80% of the electron beam's energy is at _________ of the initial beam
energy
80% line - CORRECT ANSWER✅✅✅the ________ ____________ is beam energy divided by 3.
horseshoe - CORRECT ANSWER✅✅✅The __________ has to be on in order for an electron cone
beam to be placed (adapter and cone beam)
cone beam - CORRECT ANSWER✅✅✅There are five sizes for the electron ______ _______, which
are:
6x6 (6^2)
10x10 (10^2)
15x15 (15^2)
20x20 (20^2)
25x25 (25^2)
touch detector - CORRECT ANSWER✅✅✅The _______ __________ will stop all movement with the
cones if 5 lbs of pressure is applied.
electron cone beam - CORRECT ANSWER✅✅✅With the _________ ________ ______, never operate
the gantry from outside the room (offers no clearance)
