Answers test examination
| # | choice | # | choice | # | choice | # | choice |
|---|---|---|---|---|---|---|---|
| 1 | B | 11 | C | 21 | A | 31 | D |
| 2 | A | 12 | A | 22 | D | 32 | C |
| 3 | D | 13 | A | 23 | C | 33 | A |
| 4 | C | 14 | C | 24 | B | 34 | D |
| 5 | C | 15 | D | 25 | C | 35 | B |
| 6 | C | 16 | A | 26 | A | 36 | B |
| 7 | D | 17 | C | 27 | A | 37 | B |
| 8 | B | 18 | A | 28 | D | 38 | D |
| 9 | A | 19 | D | 29 | B | 39 | B |
| 10 | A | 20 | C | 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
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 missing –› 0.5 pt deduction
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