Homework 4 Flashcards
1
Q
which of the following is true when measuring percent depth dose (PDD)?
A. the chmaber depth is constant
B. the source to chamber distance is constant
C. the source to surface distance is constant
D. the chmaber to axis distance is constant
A
C. the source to surface distance is constant
2
Q
an energy increase the \_\_\_\_\_\_\_ decreases A. depth of Dmax B. PDD at 10 cm C. point of electronic equlibrium D. none of the answers is correct
A
D. none of the answers is correct
3
Q
what is TAR an abbreviation for?
A
tissue air ratio
4
Q
the reference depth for the tissue phantom ratio, TPR, is A. dependent on measurement choice B. dmax C. 5 cm D. 10 cm
A
A. dependent on measurement choice
5
Q
what is the nominal energy of a radaition beam if the percent depth dose at 10 cm is 80% A. 20 MV B. 4 MV C. 6 MV D. 10 MV
A
A. 20 MV
