Radiography: Ch. 2 & 3 Review

A diagnostic image is produced using 90 kVp and 0.25 second. What exposure time is needed to produce the same image at 75 kVp? a 0.50 second b 0.75 second c 1.00 second d 1.25 second

a

Identify the term that describes how dark and light areas are differentiated on an image: a contrast b density c intensity d polychromatic

a

If kilovoltage is decreased with no other variations in exposure factors, the resultant image will: a appear lighter b appear darker c remain the same d either a or b

a

In dental radiography, the quality of the x-ray beam is controlled by: a kilovoltage peak b milliamperage c exposure time d source-to-receptor distance

a

No interaction: a no scatter; no ionization b no scatter; ionization c scatter; no ionization d scatter; ionization

a

Radiation produced with high kilovoltage results in: a short wavelengths b long wavelengths c less penetrating radiation d lower energy levels

a

The length of the position-indicating device is changed from 16 inches to 8 inches. The resultant intensity of the beam will be: a four times as intense b twice as intense c half as intense d one fourth as intense

a

The radiograph described in question 12 was produced with: a low kilovoltage b high kilovoltage c low milliamperage d high milliamperage

a

Which of the following accounts for 70% of all the x-ray energy produced at the anode? a general radiation b characteristic radiation c Compton scatter d coherent scatter

a

Which of the following describes primary radiation? a radiation that exits the tubehead b radiation that is created when x-rays come in contact with matter c radiation that has been deflected from its path by the interaction with matter d none of the above

a

Which of the following is not a type of electromagnetic radiation? a electrons b radar waves c microwaves d x-rays

a

Which of the following is used to increase the voltage in the high-voltage circuit? a step-up transformer b step-down transformer c autotransformer d step-up circuit

a

Which of the following statements is incorrect? a X-rays travel at the speed of sound. b X-rays have no charge. c X-rays cannot be focused to a point. d X-rays cause ionization.

a

Which of the following type of scatter occurs most often with dental x-rays? a Compton b coherent c photoelectric d none of the above

a

A diagnostic image is produced using 10 mA and 0.45 second. What exposure time is needed to produce the same image at 15 mA? a 0.25 second b 0.30 second c 0.45 second d 0.50 second

b

Identify the unit of measurement used to describe the amount of electric current flowing through the x-ray tube: a volt b ampere c kilovoltage peak d force

b

Photoelectric effect: a no scatter; no ionization b no scatter; ionization c scatter; no ionization d scatter; ionization

b

The overall blackness or darkness of an image is termed: a contrast b density c overexposure d polychromatic

b

What type of electrical charge does the electron carry? a positive charge b negative charge c no charge d positive or negative charge

b

Which of the following describes ionization? a atom without a nucleus b atom that loses an electron c atom with equal numbers of protons and electrons d none of the above

b

Which of the following is the location where x-rays are produced? a positive cathode b positive anode c negative cathode d negative anode

b

Which of the following occurs only at 70 kVp or higher and accounts for a very small part of the x-rays produced in the dental x-ray machine? a general radiation b characteristic radiation c Compton scatter d coherent scatter

b

Which of the following regulates the flow of electrical current to the filament of the x-ray tube? a high-voltage circuit b low-voltage circuit c high-voltage transformer d low-voltage transformer

b

Which of the following statements is correct? a X-rays are a form of electromagnetic radiation; visible light is not. b X-rays have more energy than does visible light. c X-rays have a longer wavelength than does visible light. d X-rays travel more slowly than does visible light.

b

Which of the following statements is incorrect? a Velocity is the speed of a wave. b Wavelength is the distance between waves. c Frequency is the number of wavelengths that pass a given point in a certain amount of time. d Frequency and wavelength are inversely related.

b

Which term describes the process by which unstable atoms undergo spontaneous disintegration in an effort to attain a more balanced nuclear state? a radiation b radioactivity c ionization d ionizing radiation

b

A radiograph that has many light and dark areas with few shades of gray is said to have: a high density b low density c high contrast d low contrast

c

Coherent scatter: a no scatter; no ionization b no scatter; ionization c scatter; no ionization d scatter; ionization

c

Identify the kilovoltage range for most dental x-ray machines: a 50 to 60 kV b 60 to 70 kV c 65 to 100 kV d greater than 100 kV

c

Identify the milliamperage range for dental radiography: a 1 to 5 mA b 4 to 10 mA c 7 to 15 mA d greater than 15 mA

c

Increasing milliamperage alone results in an image with: a high contrast b low contrast c increased density d decreased density

c

The total energy contained in the x-ray beam in a specific area at a given time is termed: a kilovoltage peak b beam quality c intensity d milliampere-second

c

Which of the following describes scatter radiation? a radiation that exits the tubehead b radiation that is more penetrating than primary radiation c radiation that has been deflected from its path by interaction with matter d none of the above

c

Which of the following does not occur when the high-voltage circuit is activated? a The unit produces an audible and visible signal. b Electrons produced at the cathode are accelerated across the tube to the anode. c X-rays travel from the filament to the target. d Heat is produced.

c

Which of the following is the location where thermionic emission occurs? a positive cathode b positive anode c negative cathode d negative anode

c

Which term describes two or more atoms that are joined by chemical bonds? a ion b ion pair c molecule d proton

c

A higher kilovoltage produces x-rays with: a greater energy levels b shorter wavelengths c more penetrating ability d all of the above

d

Compton scatter: a no scatter; no ionization b no scatter; ionization c scatter; no ionization d scatter; ionization

d

In dental radiography, the quantity of radiation produced is controlled by: a kilovoltage peak b milliamperage c exposure time d both b and c

d

Increasing milliamperage results in an increase in: a temperature of the filament b mean energy of the beam c number of x-rays produced d both a and c

d

Increasing which of these four exposure controls will increase the intensity of the x-ray beam: (1) kilovoltage, (2) milliamperage, (3) exposure time, (4) source-to-receptor distance? a 1 and 2 b 2 and 3 c 1, 2, and 3 d 1, 2, 3, and 4

d

The half-value layer is the amount of: a lead that restricts the diameter of the beam by half b copper needed to cool the anode c aluminum needed to reduce scatter radiation by half d aluminum needed to reduce x-ray beam intensity by half

d

Which of the following electrons has the greatest binding energy? a N-shell electrons b M-shell electrons c L-shell electrons d K-shell electrons

d

Which of the following is not a type of particulate radiation? a alpha particles b beta particles c protons d nucleons

d