Answers test examination
1 | A | 11 | B | 21 | B | 31 | C |
2 | A | 12 | B | 22 | A | 32 | B |
3 | A | 13 | A | 23 | C | 33 | C |
4 | D | 14 | A | 24 | D | 34 | D |
5 | B | 15 | D | 25 | C | 35 | B |
6 | B | 16 | B | 26 | A | 36 | D |
7 | A | 17 | A | 27 | A | 37 | D |
8 | C | 18 | B | 28 | D | 38 | D |
9 | C | 19 | B | 29 | D | 39 | C |
10 | D | 20 | A | 30 | C | 40 | C |
Evaluation of question 41:
Reading figure A at 125 kV and 3 mm aluminum
–› 0.065 mGy/mA s at 1 meter
The mAs value = 50 mA × 5 s = 250 mA s
The dose at 1 meter
–› 0.065 mGy/mA s × 250 mA s = 16 mGy
The entrance dose at 70 cm = 0.70 m
–› 16 mGy × (1 m / 0.70 m)2 = 33 mGy
Evaluation of question 42:
Reading figure A at 70 kV and 2 mm aluminum
–› 0.023 mGy/mA s at 1 meter
The equivalent dose for 2000 / 2 = 1000 photos
–› 1000 × 0.023 mGy/mA s × 1.5 mA s = 35 mGy at 1 meter
The dose at 3 meters
–› 35 mGy × (1 m / 3 m)2 = 3.9 mGy
Reading figure B at 70 kV and 11 mm glass
–› T = 0.2
Radiation weighting factor = wX-ray = 1 Sv/Gy
The annual effective dose on the street
–› 3.9 mGy × 1 Sv/Gy × 0.2 = 0.8 mSv
Annual limit in case of registration = 10 µSv
–› insufficient shielding
Last modified: | 12 November 2020 10.27 a.m. |