Answers test examination
| # | choice | # | choice | # | choice | # | choice |
|---|---|---|---|---|---|---|---|
| 1 | B | 11 | C | 21 | A | 31 | D |
| 2 | A | 12 | A | 22 | D | 32 | A |
| 3 | D | 13 | A | 23 | C | 33 | A |
| 4 | C | 14 | C | 24 | B | 34 | A |
| 5 | C | 15 | D | 25 | C | 35 | B |
| 6 | C | 16 | A | 26 | D | 36 | B |
| 7 | D | 17 | C | 27 | A | 37 | B |
| 8 | B | 18 | B | 28 | A | 38 | D |
| 9 | A | 19 | D | 29 | A | 39 | B |
| 10 | A | 20 | C | 30 | B | 40 | C |
Evaluation of question 41:
Reading Figure C at 90 kV and 3 mm aluminum
–› 0.08 mSv/mA·s at 1 meter
The mAs value = 6 mA × 0.15 s = 0.9 mA s
The equivalent dose at 1 meter
–› 0.08 mSv/mA·s × 0.9 mA·s = 0.07 mSv
The equivalent dose at 25 cm = 0.25 m
–› 0.07 mSv × (1 m / 0.25 m)2 = 1.1 mSv
Evaluation of question 42:
Reading Figure C at 70 kV and 3 mm aluminum
–› 0.05 mSv/mA·s at 1 meter
The equivalent dose for 2000 / 2 = 1000 photos
–› 1000 × 0.05 mSv/mA·s × 1.5 mA s = 75 mSv at 1 meter
The equivalent dose at 3 meters
–› 75 mSv × (1 m / 3 m)2 = 8 mSv
Reading Figure D at 70 kV and 11 mm glass
–› T = 0.2
The annual effective dose on the street
–› 8 mSv × 0.2 = 1.6 mSv
Annual limit in case of registration = 10 µSv
–› insufficient shielding