Deck 3: The Dental X-Ray Machine: Components and Function

Question 1

Electricity is defined as electrons in motion.

Answer 1

True

Question 2

Which of the following removes the soft x-rays for the x-ray beam as it exits the port?

A) The positioning indicating device (PID)
B) The collimator
C) The filter
D) The transformer

Answer 2

The filter

Question 3

The anode is composed of the focusing cup and the filament, and must be charged negative during x-ray production.

A) The first part of the statement is correct, the second part of the statement is NOT correct.
B) The first part of the statement is NOT correct, the second part of the statement is correct.
C) Both parts of the statement are correct.
D) Both parts of the statement are NOT correct.

Answer 3

Both parts of the statement are NOT correct.

Question 4

Dental x-ray machines contain each of the following components EXCEPT one. Which one is the EXCEPTION?

A) Control panel
B) Extension arm
C) Radioactive material
D) Tube head

Question 5

How many electrical circuits are used in a dental x-ray machine?

A) One
B) Two
C) Three
D) Four

Question 6

Which of the following best describes how x-rays are actually produced in the dental x-ray tube?

A) Radioactive particulate matter undergoes controlled disintegration.
B) Electrical current passes through an oil mixture, creating minute explosions.
C) Low milliamperage current is transformed to high kilovoltage current.
D) High-speed electrons collide with target material electrons.

Question 7

The duration of an x-ray exposure is determined by which control?

A) The timer
B) The line switch
C) The kVp selector
D) The mA selector

Question 8

What percent of the kinetic energy inside the x-ray tube is actually converted to x-radiation?

A) 99 percent
B) 50 percent
C) 25 percent
D) 1 percent

Question 9

X-rays originate at the:

A) cathode.
B) port.
C) focusing cup.
D) focal spot.

Question 10

Each of the following conditions must exist for x-rays to be produced EXCEPT one. Which one is the EXCEPTION?

A) A target capable of stopping the electrons
B) An air-filled glass tube
C) High voltage to impart speed to the electrons
D) A source of free electrons

Question 11

Which of the following is NOT a function of the tube head?

A) It allows all radiation to exit.
B) It provides grounding for the electrical components.
C) It protects the x-ray tube from accidental damage.
D) It prevents overheating of the x-ray tube.

Question 12

Amperage measures the electric potential or force that moves electrons along a conductor. Increasing the force with which the electrons move increases the penetrating potential of the x-ray beam.

A) The first statement is true. The second statement is false.
B) The first statement is false. The second statement is true.
C) Both statements are true.
D) Both statements are false.

Question 13

Which transformer corrects minor fluctuations in the current flowing through the wires?

A) The step-up transformer
B) The step-down transformer
C) The autotransformer

Question 14

Which of these statements is FALSE?

A) The positive anode and negative cathode are sealed within the x-ray tube.
B) The control panel may be integrated with the x-ray machine tube head support.
C) The exposure button should be on the end of a 3-foot timer cord.
D) The x-ray tube contains a target capable of stopping the electrons.

Question 15

The filament and target are made out of tungsten because it:

A) produces fewer electrons.
B) prevents electrons from being liberated.
C) withstands high temperatures.
D) ensures that x-rays are projected in one direction.

Question 16

Increasing which of the following would best increase the number of electrons flowing through the dental x-ray electrical circuit?

A) Impulses
B) Kilovoltage
C) Milliamperage
D) PID length

Question 17

A 1/10-second exposure equals how many impulses?

A) 4
B) 6
C) 10
D) 60

Question 18

Sixty (60) impulses is equivalent to:

A) 1/6 second.
B) 1/10 second.
C) ½ second.
D) 1 second.

Question 19

The intensity of the x-ray beam is affected by each of the following EXCEPT one. Which one is the EXCEPTION?

A) Target size
B) Kilovoltage
C) Exposure time
D) Milliamperage

Question 20

Which regulating device on the control panel measures the amount of current passing through the wires of the circuit?

A) The timer
B) The line switch
C) The kVp selector
D) The mA selector

Question 21

The collimator is a lead diaphragm that restricts the dimensions of the useful beam.

Question 22

The intensity of the beam refers to the quantity and quality of the x-rays.

Question 23

Increasing the amperage will result in a production of more x-rays.

Question 24

That part of the cathode designed to direct the free electrons toward the tungsten target of the anode is called the "focal spot."

Question 25

The metal housing of the tube head increases the safety of the x-ray machine.

Question 26

The filament is on the negative side of the vacuum tube in the dental x-ray machine.

Question 27

The tungsten anode is embedded in a core of copper to conduct heat away to a radiator.

Question 28

Voltage is the measurement of the number of electrons moving through a wire conductor.

Question 29

What does adjusting the kilovolt peak (kVp) do?

Question 30

The anode is the negative electrode (terminal) in the x-ray tube.

Question 31

Thermionic emission refers to the release of electrons from the target material during the process of incandescence.

Question 32

If the tube head is properly sealed, the port is the only place through which x-rays can escape.

Question 33

Primary beam refers to a high-energy, short wavelength x-ray beam.

Question 34

Direct current flows in pulses and changes direction.

Question 35

The step-down transformer corrects fluctuations in the current flowing through the x-ray machine.

Question 36

The x-ray beam formed at the focal spot is monochromatic.

Question 37

A small area on the tungsten target of the anode toward which the electron beam is directed is called the "focal spot."

Question 38

An x-ray beam composed of many different wavelengths is called "polychromatic."

Question 39

Dental x-ray machines may have controls for manual adjustment of kVp and mA, or these controls may be preset by the manufacturer.

Question 40

In the ON position, the line switch on the control panel energizes the low- and high-voltage circuits.

Question 41

Inside the dental x-ray machine, what does the speed of the electrons determine?

Question 42

Why are the extension arm and yoke of the x-ray machine insulated?

Question 43

What is the name of the device that allows the amount of current passing through the wires of the circuit to be changed?

Question 44

What is the term for the measurement of the number of electrons moving through a wire conductor?

Question 45

What is the purpose of a "deadman" exposure switch?

Question 46

What does kVp measure?

Question 47

In the cathode, the wire filament is recessed into what?

Question 48

What is the term for the process by which electrons are created at the filament wire of the cathode?

Question 49

Who is responsible for the radiation dose incurred by the patient during x-ray exposure?