NMCTB : Radiation Physics and Detection Practice Questions

15 mCi is equal to how many GBq?

0.56 GBq

Convert 5 REM to mSv.

50 mSv

You are doing a linearity test with Tc-99m. Your calculated activity on Monday morning at 8 AM is 180 mCi. On the same day at noon, what is your expected activity?

113 mCi

The consequence of an unstable neutron-rich nucleus is?

production of a beta negative particle

Your counting system has a 75% efficiency. Your wipe sample is 925 cpm with a background of 22 cpm. If your action limit is 2,000 dpm, what should you do?

record the wipe as 1,204

Generator systems are only possible when?

the half-life of the parent is longer than the half-life of the daughter

What is the physical half-life and energy peak of I-123?

13 hours; 159 keV

If an exposure rate is 6 mR/hr at 2 meters, what is the exposure rate at 1.5 meters?

11 mR/hr

If two elements have the same atomic number, but different mass numbers, how are they related?

Isotopes

All of the following are examples of isobaric decay, EXCEPT?

Alpha decay

A therapy patient should be monitored with which instrument?

Ionization chamber

What type of interaction occurs when a photon interacts with an inner shell electron, and all of the energy is absorbed and given to that electron?

Photoelectric

A radiopharmaceutical has a half-life of 3 hours. If you have 120 mCi now, how long before you have 19 mCi?

8 hours

What is the effective half-life of a Tc-labeled radiopharmaceutical with a 90-minute biological half-life?

1.2 hours