4. Radiation Physics

Question 1

What is intensity in the context of the X-ray beam?

Answer 1

Total amount of energy in the X-ray beam.

Question 2

What controls the quantity of the X-ray beam?

Answer 2

Tube current (mA) and exposure time (sec).

Question 3

What controls the quality of the X-ray beam?

Answer 3

Tube voltage (kVp).

Question 4

How does tube voltage (kVp) affect the X-ray beam?

Answer 4

Increases both the number of photons and their energy.

Question 5

How does exposure time affect the X-ray beam?

Answer 5

Increases the number of photons but not their energy.

Question 6

How does tube current (mA) affect the X-ray beam?

Answer 6

Increases the number of photons without changing energy.

Question 7

What is the role of filtration in X-ray production?

Answer 7

Removes low-energy photons, improving quality but reducing quantity.

Question 8

What is collimation in X-ray production?

Answer 8

Restricts beam size, reducing photon count without affecting energy.

Question 9

What does the inverse square law state about X-ray intensity?

Answer 9

Intensity decreases with increasing distance; doubling distance reduces intensity by a factor of 4.

Question 10

How does tube voltage (kVp) influence quantity and quality?

Answer 10

Increases both quantity and quality.

Question 11

What is the effect of tube current (mA) on quantity and quality?

Answer 11

Increases quantity; no effect on quality.

Question 12

How does exposure time impact quantity and quality?

Answer 12

Increases quantity; no effect on quality.

Question 13

What is mAs and how does it affect X-ray quantity?

Answer 13

mA multiplied by exposure time, increases quantity with no effect on quality.

Question 14

How does source-to-object distance influence X-ray quantity and quality?

Answer 14

Decreases quantity; no effect on quality.

Question 15

What is the impact of filtration on X-ray quantity and quality?

Answer 15

Decreases quantity and increases quality.

Question 16

What controls the density of a radiograph?

Answer 16

Controlled by mAs.

Question 17

How is contrast on a radiograph controlled?

Answer 17

Controlled by kVp.

Question 18

What are the characteristics of high contrast in radiographs?

Answer 18

Low kVp; high contrast with fewer shades of gray.

Question 19

What are the characteristics of low contrast in radiographs?

Answer 19

High kVp; low contrast with more shades of gray.

Question 20

What is the relationship between mA and exposure time in maintaining radiograph density?

Answer 20

Inversely proportional to maintain the same density.

Question 21

What type of kVp is ideal for caries detection?

Answer 21

Low kVp for high contrast and caries detection.

Question 22

What type of kVp is ideal for viewing bone loss?

Answer 22

High kVp for low contrast and bone loss visualization.

Question 23

What are key takeaways regarding beam intensity and exposure factors?

Answer 23

Intensity depends on mA, exposure time, and kVp; filtration improves quality but reduces quantity; collimation shapes the beam and reduces exposure.