Question

24 multiple choice 1 point
if mas decreases, exposure will ?
○ increase
○ decrease
○ stay the same

25 fill in the blank 1 point
exposure was made using 15 mas, 65 kvp, 40 sid. what is the prime factor’s value if beam quantity is double?
type your answer...

26 multiple choice 1 point
what is the relationship b/t ma and time while maintaining the beam?
○ directly proportional
○ inversely proportional

Explanation:

Question 24

mAs (milliampere - seconds) is directly related to exposure in radiography. If mAs decreases, the amount of radiation produced (exposure) also decreases.

Step1: Recall the relationship between mAs and beam quantity. Beam quantity is directly proportional to mAs.

Step2: If beam quantity is doubled, mAs should be doubled. Initial mAs is 15, so new mAs is \(15\times2 = 30\). The prime factor here related to mAs change (since kVp and SID don't affect the mAs - beam quantity direct proportion here) is that mAs is doubled, so the factor is 2.

To maintain the beam (exposure), \(mAs=mA\times time\). So if one (mA or time) increases, the other must decrease proportionally, meaning they are inversely proportional.

Answer:

B. decrease

Question 25