IRRSP LATEST 2026 TEST PAPER QUESTIONS AND
ANSWERS GRADED A+
✔✔11 Ci - ✔✔A cobalt source has decayed from its original activity after 3 half-lives.
Originally it was 88 Ci. Its current activity is:
a. 44 Ci
b. 22 Ci
c. 11 Ci
d. 8 Ci
✔✔253 ft - ✔✔A cobalt source of 73 Ci is exposed for a full 60 min. Assume a 14.0
R/hr/Ci @ 1ft factor, shooting through a 3 half-value collimator. What would the
restricted area (2 mr/hr) be on the cold or collimated side of the collimator? (Use Inverse
Square Law (Intensity 1/Intensity 2) = (Distance 2 Squared/ Distance 1 Squared))
a. 149 ft
b. 162 ft
c. 211 ft
d. 253 ft
✔✔Stop ball - ✔✔The ball on a source assembly that prevents the source from exiting
through the back of the camera is called:
a. Stop ball
b. Pigtail ball
c. Safety stop ball
d. Retraction inhibitor ball
✔✔Characteristics of source decay - ✔✔Emission of gamma rays, alpha rays and beta
rays is considered what?
a. Characteristics of source decay
b. Material is stable
c. Material is unbalanced
d. Leaking source
✔✔More energy (Shorter wavelength) - ✔✔To penetrate a thicker or denser material,
you would need a source with:
a. More curies
b. More activity
c. More energy (Shorter wavelength)
d. Less energy (Longer wavelength)
✔✔A number - ✔✔An element's weight is the:
a. A number
b. Z number
c. Atomic number
d. Number of neutrons
,✔✔Protons - ✔✔An element is identified by the number of __________ in its nucleus.
a. Electrons
b. Protons
c. Neutrons
d. Photons
✔✔Reddening of the skin - ✔✔The first indication of an extremity radiation
overexposure is:
a. Reddening of the skin
b. Hair loss
c. Nausea
d. Blisters
✔✔More penetrating - ✔✔Gamma radiation has a shorter wavelength than visible light,
therefore making it:
a. Less penetrating
b. More penetrating
c. Brighter
d. Less stable
✔✔5 mR/hr - ✔✔A radiation area is defined as "an area accessible to individuals, in
which they could receive......."
a. 2 mR/hr
b. 5 mR/hr
c. 50 mR/hr
d. 100 mR/hr
✔✔100 mR/hr - ✔✔A high radiation area is defined as "an area accessible to
individuals, in which they could receive...."
a. 2 mR/hr
b. 5 mR/hr
c. 50 mR/hr
d. 100 mR/hr
✔✔B - ✔✔A member of the public or unmonitored individual is allowed to receive up to,
but not to exceed:
(Answer with A, B, C, or D)
a. 2 mR/hr, 500 mR/year
b. 2 mR/hr, 100 mR/year
c. 5 mR/hr, 100 mR/year
d. 5 mR/hr, 500 mR/year
✔✔High radiation area and radiation area - ✔✔When performing radiography in the
field, regulations require the radiographer to post with physical barriers or signs the:
, a. Restricted area
b. Radiation area
c. High radiation area and radiation area
d. Restricted area and the high radiation area
✔✔D - ✔✔A restricted area is defined as an area:
(Answer with A, B, C, or D)
a. That is controlled and posted
b. That must be posted and where an individual may receive up to 5 mR/hr
c. That must be posted and where an individual may receive up to 100 mR/hr
d. To which access is restricted for the purpose of controlling radiation exposure
✔✔8 mR - ✔✔A radiographer and assistant are standing in a 2 mR/hr field. What would
the assistant's total dose be after 4 hours?
a. 2 mR
b. 4 mR
c. 6 mR
d. 8 mR
✔✔60 mR - ✔✔You have 24 exposures to make. Your shot time is 5 min per exposure
and you're showing 30 mR/hr. What will you total dose be at the end of the shift?
a. 30 mR
b. 60 mR
c. 120 mR
d. 240 mR
✔✔111.8 ft - ✔✔A radiographer is receiving 100 mR at the crank assembly. The crank
assembly is 25ft in length. Where would the "Radiation Area" sign be posted? (Use
Inverse Square Law)
a. 111.8 ft
b. 221.3 ft
c. 343.7 ft
d. 176.8 ft
✔✔30 min - ✔✔A radiographer is receiving 100 mR/hr at the crank assembly. The crank
assembly is 25 ft in length. How long will it take for the radiographer to receive a total
dose of 50 mR?
a. 30 min
b. 60 min
c. 90 min
d. 120 min
✔✔5 R per year - ✔✔A non-declared pregnant radiographer or assistant may receive no
more than:
a. 0.5 rem per year
b. 5000 rem per year
ANSWERS GRADED A+
✔✔11 Ci - ✔✔A cobalt source has decayed from its original activity after 3 half-lives.
Originally it was 88 Ci. Its current activity is:
a. 44 Ci
b. 22 Ci
c. 11 Ci
d. 8 Ci
✔✔253 ft - ✔✔A cobalt source of 73 Ci is exposed for a full 60 min. Assume a 14.0
R/hr/Ci @ 1ft factor, shooting through a 3 half-value collimator. What would the
restricted area (2 mr/hr) be on the cold or collimated side of the collimator? (Use Inverse
Square Law (Intensity 1/Intensity 2) = (Distance 2 Squared/ Distance 1 Squared))
a. 149 ft
b. 162 ft
c. 211 ft
d. 253 ft
✔✔Stop ball - ✔✔The ball on a source assembly that prevents the source from exiting
through the back of the camera is called:
a. Stop ball
b. Pigtail ball
c. Safety stop ball
d. Retraction inhibitor ball
✔✔Characteristics of source decay - ✔✔Emission of gamma rays, alpha rays and beta
rays is considered what?
a. Characteristics of source decay
b. Material is stable
c. Material is unbalanced
d. Leaking source
✔✔More energy (Shorter wavelength) - ✔✔To penetrate a thicker or denser material,
you would need a source with:
a. More curies
b. More activity
c. More energy (Shorter wavelength)
d. Less energy (Longer wavelength)
✔✔A number - ✔✔An element's weight is the:
a. A number
b. Z number
c. Atomic number
d. Number of neutrons
,✔✔Protons - ✔✔An element is identified by the number of __________ in its nucleus.
a. Electrons
b. Protons
c. Neutrons
d. Photons
✔✔Reddening of the skin - ✔✔The first indication of an extremity radiation
overexposure is:
a. Reddening of the skin
b. Hair loss
c. Nausea
d. Blisters
✔✔More penetrating - ✔✔Gamma radiation has a shorter wavelength than visible light,
therefore making it:
a. Less penetrating
b. More penetrating
c. Brighter
d. Less stable
✔✔5 mR/hr - ✔✔A radiation area is defined as "an area accessible to individuals, in
which they could receive......."
a. 2 mR/hr
b. 5 mR/hr
c. 50 mR/hr
d. 100 mR/hr
✔✔100 mR/hr - ✔✔A high radiation area is defined as "an area accessible to
individuals, in which they could receive...."
a. 2 mR/hr
b. 5 mR/hr
c. 50 mR/hr
d. 100 mR/hr
✔✔B - ✔✔A member of the public or unmonitored individual is allowed to receive up to,
but not to exceed:
(Answer with A, B, C, or D)
a. 2 mR/hr, 500 mR/year
b. 2 mR/hr, 100 mR/year
c. 5 mR/hr, 100 mR/year
d. 5 mR/hr, 500 mR/year
✔✔High radiation area and radiation area - ✔✔When performing radiography in the
field, regulations require the radiographer to post with physical barriers or signs the:
, a. Restricted area
b. Radiation area
c. High radiation area and radiation area
d. Restricted area and the high radiation area
✔✔D - ✔✔A restricted area is defined as an area:
(Answer with A, B, C, or D)
a. That is controlled and posted
b. That must be posted and where an individual may receive up to 5 mR/hr
c. That must be posted and where an individual may receive up to 100 mR/hr
d. To which access is restricted for the purpose of controlling radiation exposure
✔✔8 mR - ✔✔A radiographer and assistant are standing in a 2 mR/hr field. What would
the assistant's total dose be after 4 hours?
a. 2 mR
b. 4 mR
c. 6 mR
d. 8 mR
✔✔60 mR - ✔✔You have 24 exposures to make. Your shot time is 5 min per exposure
and you're showing 30 mR/hr. What will you total dose be at the end of the shift?
a. 30 mR
b. 60 mR
c. 120 mR
d. 240 mR
✔✔111.8 ft - ✔✔A radiographer is receiving 100 mR at the crank assembly. The crank
assembly is 25ft in length. Where would the "Radiation Area" sign be posted? (Use
Inverse Square Law)
a. 111.8 ft
b. 221.3 ft
c. 343.7 ft
d. 176.8 ft
✔✔30 min - ✔✔A radiographer is receiving 100 mR/hr at the crank assembly. The crank
assembly is 25 ft in length. How long will it take for the radiographer to receive a total
dose of 50 mR?
a. 30 min
b. 60 min
c. 90 min
d. 120 min
✔✔5 R per year - ✔✔A non-declared pregnant radiographer or assistant may receive no
more than:
a. 0.5 rem per year
b. 5000 rem per year
