Additional MCQs

Question 1

A fluoroscopic system has automatic brightness control in which the kV is adjusted manually and the mA varies as a function of patient thickness. For a given patient thickness, as the kV is decreased…

• the mA decreases and patient entrance skin dose is constant
• the mA decreases and patient entrance skin dose increases
• the mA increases and patient entrance skin dose decreases
• the mA increases and patient entrance skin dose increases

Answer 1

-the mA increases and patient entrance skin dose increases

Question 2

The x-ray tube current is dictated by the…

anode rotation speed
kilovoltage
filament current and kilovoltage
filament current
focal spot size

Answer 2

filament current and kilovoltage

Question 3

As the kV is increased, the contrast between soft tissue and bone seen in a radiographic image will…

decrease regardless of the choice of image receptor

increase regardless of the choice of image receptor

Answer 3

decrease regardless of the choice of image receptor

Question 4

The intensity of an x-ray beam increases and the subject contrast remains unchanged by…

increasing kVp
increasing mAs
decreasing kVp
decreasing mAs

Answer 4

increasing mAs

Question 5

How much change in kVp doubles the amount of film density/exposure?

15%
25%
50%
100%

Answer 5

15%

Question 6

Patient skin dose rate will decrease with kV only when the…

collimators are fully open
grid is removed
pulse rate is increased
tube current is reduced

Answer 6

tube current is reduced