Chapter 3

Question 1

What determines the energy and penetrating power of radiation?

Answer 1

wavelength

Question 2

X-rays with shorter wavelengths are ___, have more ___ and more ___ power.

Answer 2

stronger; energy; penetrating

Question 3

What is used to describe the mean energy and penetrating power of an x-ray beam?

Answer 3

quality

Question 4

what is controlled by kilovoltage?

Answer 4

quality

Question 5

what is a measurement of force that refers to the potential difference between two electrical charges?

Answer 5

voltage

Question 6

If voltage is ___ , the ___ of electrons is increased.

Answer 6

increased; speed

Question 7

T/F. Electrons strike targets with greater force and energy resulting in penetrating x-rays and short wavelengths.

Answer 7

true

Question 8

1 kV = ___ volts

Answer 8

1000

Question 9

T/F. The greater the kV, the less penetrating dental x-rays are. They use less energy and have longer wavelengths.

Answer 9

False, the greater the kV, the MORE penetrating dental x-rays are. They use MORE energy and have SHORTER wavelengths.

Question 10

Today’s units use ___ - ___ kV.

Answer 10

60 - 70

Question 11

What does 70 kVp mean?

Answer 11

the peak/maximum voltage is 70,000 volts of an alternating current (AC)

Question 12

kV regulates ___ across the x-ray tube and controls the ___ of electrons.

Answer 12

voltage; speed

Question 13

what is the overall darkness or blackness of an image.

Answer 13

density

Question 14

high kV = ___ density = too ___

low kV = ___ density = too ___

Answer 14

high; dark

low; light

Question 15

What refers to how sharply dark and light areas are differentiated or separated on an image?

Answer 15

contrast

Question 16

high contrast = ___ kVp

low contrast = ___ kVp

Answer 16

low

high

Question 17

What controls the length of exposures in impulses or seconds?

Answer 17

exposure time

Question 18

60 impulses = ___ seconds
30 impulses = ___ seconds
15 impulses = ___ seconds

Answer 18

1. 00
2. 25
3. 25

Question 19

kV = quaLity and mA = quaNity

Answer 19

k-l-m-n

Question 20

what measures the number of electrons flowing thru the cathode filament?

Answer 20

ampere

Question 21

Increasing amperage ___ number of electrons traveling from cathode to anode.

Answer 21

increases

Question 22

What controls the temperature of the cathode filament?

Answer 22

milliampere (mA)

Question 23

What milliampere produces an excessive amount of heat?

Answer 23

> 15 mA, today’s units 6-8 mA

Question 24

what controls the amount of current that flows through the cathode filament?

Answer 24

milliampere (mA)

Question 25

The higher mA, the ___ the filament temperature and the ___ the number/quanity of electrons.

Answer 25

higher; greater

Question 26

high mA = ___ density = too ___ | low mA = ___ density = too ___

Answer 26

high; dark | low; light

Question 27

Exposure time and mA are ___ related.

Answer 27

inversely increase mA = decreases time decrease mA = increase time

Question 28

Define intensity.

Answer 28

quantity x quality / area x exposure rate

Question 29

T/F. Increases in kV, mA, time and distance all increase intensity.

Answer 29

False, kV, mA, and time increase intensity. Distance DECREASES intensity

Question 30

What is the inverse square law?

Answer 30

intensity of radiation is inversely proportional to the square of the distance from the source of radiation

Question 31

if the distance is DOUBLED ---- beam is ___ as intense if the distance is HALVED ---- beam is ___ as intense If the distance is TRIPLED ---- beam is ___ as intense If the distance is QUADRUPLED ---- beam is ___ as intense

Answer 31

1/4 4 times 1/9 1/16

Question 32

If the PID length is changed from 8" to 16" (doubled) how is the intensity of the beam affected?

Answer 32

1/4 as intense

Question 33

if the PID length is changed from 16" to 8" (halved), how is the intensity of the beam affected?

Answer 33

4 times as intense

Question 34

The thickness of ___ placed in the path of the x-ray beam reduces the intensity by 1/2

Answer 34

aluminum

Question 35

What does it mean if an x-ray beam with a half-value layer (hvl) of 2.7mm?

Answer 35

that a thickness of 2.7mm of aluminum is placed in the path of the beam to reduce the intensity by 1/2

Question 36

Aluminum filters are place in the path of the beam to remove ___ energy x-rays.

Answer 36

low