equations & conversions

Question 1

1 GBq =

100 MBq
1,000 MBq
10,000 MBq
100,000 MBq

Answer 1

1,000 MBq

Question 2

1 MBq =

0.001 kBq
0.01 kBq
0.1 kBq
100 kBq
1,000 kBq

Answer 2

1,000 kBq

Question 3

1 Ci =

0.37 GBq
3.7 GBq
37 GBq
370 GBq

Answer 3

37 GBq

Question 4

1 mCi =

0.37 MBq
3.7 MBq
37 MBq
370 MBq

Answer 4

37 MBq

Question 5

1 Gy =

10 rad
100 rad
1,000 rad
1,000,000 rad

Answer 5

100 rad

Question 6

1 Sv =

10 rem
100 rem
1,000 rem
1,000,000 rem

Answer 6

100 rem

Question 7

percent error/percent difference

Answer 7

|expected-actual/expected| x 100%

Question 8

cpm to dpm using well counter efficiency

Answer 8

dpm = net cpm/efficiency as a decimal

Question 9

inverse square law

Answer 9

(I1)(D1)^2 = (I2)(D2)^2

Question 10

change in exposure rate due to shielding

Answer 10

I = I0 x e^ -(0.693)(x/HVL)

x = thickness of shielding material
HVL = half value layer of given material

Question 11

effective half life

Answer 11

Te = (Tp x Tb) / (Tp + Tb)

Question 12

well counter efficiency

Answer 12

% efficiency = cpm / (dpm x mean number per disintegration) x 100%

Question 13

decay calculation

Answer 13

At = A0 x e^ -0.693(t/t1/2)

Question 14

clark’s formula

Answer 14

(child’s weight in lbs)(adult dose) / 150 lbs

Question 15

webster’s formula

Answer 15

(age in years + 1 / age +7) x adult dose

Question 16

young’s formula

Answer 16

(age in years/age + 12) x adult dose

Question 17

HVL of lead for F18

Answer 17

4.1 mm