Answers test examination
| # | choice | # | choice | # | choice |
|---|---|---|---|---|---|
| 1 | B | 11 | C | 21 | D |
| 2 | A | 12 | A | 22 | C |
| 3 | D | 13 | A | 23 | B |
| 4 | C | 14 | C | 24 | C |
| 5 | C | 15 | D | 25 | A |
| 6 | B | 16 | D | 26 | D |
| 7 | D | 17 | B | 27 | D |
| 8 | B | 18 | D | 28 | B |
| 9 | A | 19 | C | 29 | A |
| 10 | A | 20 | A | 30 | B |
Evaluation of question 31:
Reading Figure C at110 kV and 3 mm aluminum
–› 0.14 mSv/mA·s at 1 meter
mAs-value = 6 mA × 0.3 s = 1.8 mA·s
Equivalent dose at 1 meter
–› 0.14 mSv/mA·s × 1,8 mA·s = 0.25mSv
Distance focus - skin = 50 cm = 0.50 m
Equivalent skin dose = 0.25 mSv × (1 m / 0.50 m)2 = 1.0 mSv
Evaluation of question 32:
Reading Figure C at 50 kV and 2 mm aluminum
–› 0.05 mSv/mA·s at 1 meter
mAs-value = 0.005 mA × 25 s = 0.125 mA·s
Equivalent dose at 1 meter
–› 0.05 mSv/mA·s × 0.125 mA·s = 0.0063 mSv
Distance focus - skin = 5 cm = 0.05 m
Equivalent skin dose
–› 0.0063 mSv × (1 m / 0.05 m)2 = 2.5 mSv
Number of inspections = 30 per day × 200 d/y = 6000 per year
Annual quivalent skin dose
–› 2.5 mSv × 6000 = 15·103 mSv = 15 Sv