4/19/26, 2:18 PM NRRPT Prep Radiation Fundamentals Study Guide Exam Latest 2026/2027 Updated Verified Questions and Solutions A+ Pass Gu…
NRRPT Prep Radiation Fundamentals Study Guide Exam
Latest 2026/2027 Updated Verified Questions and Solutions
A+ Pass Guaranteed
Question Number: 1
Fundamentals of Radiation Protection
A low energy alpha detector is usually effective if the detector is distant from the
source.
A) 1/4 inch
B) 1/2 inch
C) 1 inch
D) 1 1/2 inches
E) 2 inches
The correct answer is: A
Low energy alpha particles can only travel less than 1/2 inch in air. Therefore, one
must be closer than this to detect them.
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,4/19/26, 2:18 PM NRRPT Prep Radiation Fundamentals Study Guide Exam Latest 2026/2027 Updated Verified Questions and Solutions A+ Pass Gu…
Question Number: 2
Fundamentals of Radiation Protection
A sample of I-131 (half life = 8 days) is kept for 80 days, at which time the activity is 1
µCi . What was the original activity?
A) 2.0 mCi
B) 1.0 mCi
C) 1.5 mCi
D) 3.5 mCi
E) 4.0 mCi
The correct answer is: B
After 10 half lives, the remaining activity is approximately 1000th of the original
amount. Therefore, if there was 1
µCi left after 10 half lives, then there must have been 1000 times more to start with.
Hence, 1 µCi * 1000 = 1 mCi.
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,4/19/26, 2:18 PM NRRPT Prep Radiation Fundamentals Study Guide Exam Latest 2026/2027 Updated Verified Questions and Solutions A+ Pass Gu…
Question Number: 3
Fundamentals of Radiation Protection
A sample of radioactive material is reported to contain 2000 picocuries of activity.
Express this value as
disintegrations per minute.
A) 370 dpm
B) 900 dpm
C) 3770 dpm
D) 4440 dpm
E) 5320 dpm
The correct answer is: D
dps = (2000 pCi)(1 x 10^-12Ci/pi )(3.7x10^10 dps/Ci) dps = 74
dpm = (74 dps) (60 sec/min)
dpm = 4440
Remember to convert to disintegrations per minute not DISINTEGRATIONS PER
SECOND.
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, 4/19/26, 2:18 PM NRRPT Prep Radiation Fundamentals Study Guide Exam Latest 2026/2027 Updated Verified Questions and Solutions A+ Pass Gu…
Question Number: 4
Fundamentals of Radiation Protection
A sample of wood from an ancient forest showed 93.75% of the Carbon-14 decayed.
How many half lives did the carbon go through?
A) 1
B) 2
C) 3
D) 4
E) 5
The correct answer is: D
1 half life = 50% remaining
2 half lives = 25% remaining
3 half lives = 12.5% remaining
4 half lives = 6.25% remaining
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NRRPT Prep Radiation Fundamentals Study Guide Exam
Latest 2026/2027 Updated Verified Questions and Solutions
A+ Pass Guaranteed
Question Number: 1
Fundamentals of Radiation Protection
A low energy alpha detector is usually effective if the detector is distant from the
source.
A) 1/4 inch
B) 1/2 inch
C) 1 inch
D) 1 1/2 inches
E) 2 inches
The correct answer is: A
Low energy alpha particles can only travel less than 1/2 inch in air. Therefore, one
must be closer than this to detect them.
pa… 1/336
,4/19/26, 2:18 PM NRRPT Prep Radiation Fundamentals Study Guide Exam Latest 2026/2027 Updated Verified Questions and Solutions A+ Pass Gu…
Question Number: 2
Fundamentals of Radiation Protection
A sample of I-131 (half life = 8 days) is kept for 80 days, at which time the activity is 1
µCi . What was the original activity?
A) 2.0 mCi
B) 1.0 mCi
C) 1.5 mCi
D) 3.5 mCi
E) 4.0 mCi
The correct answer is: B
After 10 half lives, the remaining activity is approximately 1000th of the original
amount. Therefore, if there was 1
µCi left after 10 half lives, then there must have been 1000 times more to start with.
Hence, 1 µCi * 1000 = 1 mCi.
pa… 2/336
,4/19/26, 2:18 PM NRRPT Prep Radiation Fundamentals Study Guide Exam Latest 2026/2027 Updated Verified Questions and Solutions A+ Pass Gu…
Question Number: 3
Fundamentals of Radiation Protection
A sample of radioactive material is reported to contain 2000 picocuries of activity.
Express this value as
disintegrations per minute.
A) 370 dpm
B) 900 dpm
C) 3770 dpm
D) 4440 dpm
E) 5320 dpm
The correct answer is: D
dps = (2000 pCi)(1 x 10^-12Ci/pi )(3.7x10^10 dps/Ci) dps = 74
dpm = (74 dps) (60 sec/min)
dpm = 4440
Remember to convert to disintegrations per minute not DISINTEGRATIONS PER
SECOND.
pa… 3/336
, 4/19/26, 2:18 PM NRRPT Prep Radiation Fundamentals Study Guide Exam Latest 2026/2027 Updated Verified Questions and Solutions A+ Pass Gu…
Question Number: 4
Fundamentals of Radiation Protection
A sample of wood from an ancient forest showed 93.75% of the Carbon-14 decayed.
How many half lives did the carbon go through?
A) 1
B) 2
C) 3
D) 4
E) 5
The correct answer is: D
1 half life = 50% remaining
2 half lives = 25% remaining
3 half lives = 12.5% remaining
4 half lives = 6.25% remaining
pa… 4/336
