1 ARRT Nuclear Medicine Boards (Math and Stats) Questions and Answers | Already passed | Latest Update The radiation intensity from a point source of 99mTc is 9 mR/hr at 3 m from the source. If the distance is changed to 9 m, what is the new radiation intensity? A. 0.5 mR/h r B. 1.0 mR/hr C. 2.0 mR/hr D. 3.0 mR/hr 🗸🗸: B. 1.0 mR/hr The inverse square law results in the radiation intensity quadrupling if the distance from the source is halved, or it results in the radiation intensity decreasing to one fourth of its value if the distance is doubled. A technologist is sitting near a bone mineral densitometer, which is a point source of x -rays. If the x -
ray intensity at 1 m from the x -ray beam is 0.20 mR/hr, to what distance from the x -ray beam should 2 the technologist move to decrease total weekly exposure to the occupational limit of 2 mR for a 40 -
hour workweek? A. 0.5 m B. 1.5 m C. 2.0 m D. 2.5 m 🗸🗸: C. 2.0 m The inverse square law results in the radiation intensity quadrupling if the distance from the source is halved, o r it results in the radiation intensity decreasing to one fourth of its value if the distance is doubled. The unit of intensity is mR/hr, but a 40 -hour workweek must be taken into consideration when calculating the final answer. 10 mCi is equal to how man y becquerels? A. 370 Bq B. 370 kBq C. 370 MBq D. 370 GBq 🗸🗸: C. 370 MBq 3 1 curie = 3.7 1010 disintegrations per second [dps], and in SI units, 1 Bq = 1 dps; therefore, 1 Ci = 37 GBq and 1 mCi = 37 MBq. In this problem, activity in Bq = 10mCi * (10^ -3 Ci/mCi) * (3.7 *10^10 Bq/Ci) 20 mCi is equal to how many becquerels? a. 0.74 GBq b. 0.37 GBq c. 0.54 GBq d. 0.20 GBq 🗸🗸: A. 0.74 GBq 1 curie = 3.7 1010 disintegrations per second [dps], and in SI units 1 Bq = 1 dps; therefore, 1 Ci = 37 GBq and 1 mCi = 37 MBq. In this problem, activity in Bq = 20 mCi * ( 10^ -3 Ci/mCi) * (3.7*10^10 Bq/Ci) The dose equivalent for occupational whole -body exposure is commonly limited to 50 mSv. How many rem is this? A. 5000 rem B. 500 rem
ray intensity at 1 m from the x -ray beam is 0.20 mR/hr, to what distance from the x -ray beam should 2 the technologist move to decrease total weekly exposure to the occupational limit of 2 mR for a 40 -
hour workweek? A. 0.5 m B. 1.5 m C. 2.0 m D. 2.5 m 🗸🗸: C. 2.0 m The inverse square law results in the radiation intensity quadrupling if the distance from the source is halved, o r it results in the radiation intensity decreasing to one fourth of its value if the distance is doubled. The unit of intensity is mR/hr, but a 40 -hour workweek must be taken into consideration when calculating the final answer. 10 mCi is equal to how man y becquerels? A. 370 Bq B. 370 kBq C. 370 MBq D. 370 GBq 🗸🗸: C. 370 MBq 3 1 curie = 3.7 1010 disintegrations per second [dps], and in SI units, 1 Bq = 1 dps; therefore, 1 Ci = 37 GBq and 1 mCi = 37 MBq. In this problem, activity in Bq = 10mCi * (10^ -3 Ci/mCi) * (3.7 *10^10 Bq/Ci) 20 mCi is equal to how many becquerels? a. 0.74 GBq b. 0.37 GBq c. 0.54 GBq d. 0.20 GBq 🗸🗸: A. 0.74 GBq 1 curie = 3.7 1010 disintegrations per second [dps], and in SI units 1 Bq = 1 dps; therefore, 1 Ci = 37 GBq and 1 mCi = 37 MBq. In this problem, activity in Bq = 20 mCi * ( 10^ -3 Ci/mCi) * (3.7*10^10 Bq/Ci) The dose equivalent for occupational whole -body exposure is commonly limited to 50 mSv. How many rem is this? A. 5000 rem B. 500 rem
