ch 1-4 Flashcards
A transformer is used to step up or step down electricity; it receives:
High voltage and low amperage
In x-ray technology, potential difference refers to the difference between:
The charge between the cathode and the anode of the x-ray tube
The purpose of a transformer is to
Increase the voltage in a step-up transformer
Rectifiers are used in the x-ray circuit to ensure that:
The current flows through the x-ray tube in a continuous direction
The high-frequency x-ray unit is _________ efficient than a/an __________ unit.
more, single-phase
The cathode in the x-ray tube is a coiled _________. It is made of ______________.
wire, tungsten
The filament circuit is used to:
Send voltage to the cathode to heat it
The anode rotates in order to:
. Dissipate the heat emitted in the production of x-rays
X-rays are produced when ________ electrons are attracted to _______________ by an electromagnetic force.
negative, a positive anode
Heat builds up on the anode and must be dissipated by:
A rotating anode and a tungsten alloy target
The rotor circuit is responsible to activate:
The rotating anode
The exposure switch must ____________ and _________________.
terminate when the exposure is complete, must not reexpose until the switch is released and reactivated
The line voltage compensator is situated_______ and controls the ________.
on the incoming line; incoming voltage
A ground wire is installed in every generator. Which of the following statements is correct?
It provides an alternative route for the electricity.
Direct current is necessary to produce x-rays; the current must flow through the x-ray tube:
From the cathode to the anode without interruption
produces one positive pulse and then one matching negative pulse; An electric current that reverses its direction many times a second
alternating current
The strength of an electric current, measured in amperes
amperage
An electrode with a positive charge; An electrode with a positive charge
“Positive Andy”
Anode
Because of the angle of the anode target, the x-ray beam has greater intensity on the cathode side of the tube, with the intensity diminishing toward the anode side. Used when a patient is thicker on one side of its anatomy
Anode Heel effect
Occurs during the production of x-rays when a projectile electron completely avoids the orbital electrons of the tungsten atom and travels very close to its nucleus. The very strong electrostatic force of the nucleus causes the electron to suddenly ‘slow down’. As the electron loses energy, it suddenly changes its direction and the energy loss then reappears as an x-ray photon.
Bremsstrahlung radiation
A negatively charged electrode within the x-ray tube. It comprises a filament and a focusing cup.
cathode
Produced when a projectile electron interacts with an electron from the inner (K) shell of the tungsten atom. When the K-shell electron is ejected from its orbit; an outer shell electron drops into the open position and thereby creates an energy difference. The energy difference is emitted as an x-ray photon.
characteristic radiation or interactions
A course or pathway through which an electrical current passes
circuit
An automatic safety device for stopping the flow of current in an electrical circuit
circuit breaker
An electric current flowing in one direction only.
ex: flashlight
direct current
The switch that generates the power to the x-ray tube. A remote-control device that permits current to flow through the circuit.
exposure switch
what are the two stages of the exposure switch
The first stage activates the rotating anode and boosts the filament circuit. The second stage activates the exposure, and x-rays are produced.
A coiled tungsten wire that is the source of electrons during x-ray production. Part of the cathode, has two sizes
Filament
The physical area of the target that is bombarded by electrons during x-ray production
focal spot
When the anode is bombarded with radiation, it becomes very hot. This can expand the size of the anode and therefore decrease sharpness.
Focal spot bloom
X-rays are described as:
Invisible, but they travel in straight lines at the speed of light
An element is the smallest part of a substance. Which of the following statements is true?
a. The element is combined with a proton.
b. The smallest part of an element is an atom.
c. The element is composed of neutrons and particles.
d. Electrons circle the element in random order.
b. The smallest part of an element is an atom.
The electrons are held in place by:
The positive charge of the protons
On the table of the elements:
The elements are arranged in specific groups.
. Matter and energy are basic to every substance on earth. Which of the following statements is true?
a. The principle characteristic of matter is mass or weight.
b. The principle characteristics of energy are time and space.
c. Matter represents motion and frequency.
d. Energy cannot be created out of atoms and molecules.
a. The principle characteristic of matter is mass or weight.
The electromagnetic spectrum represents:
The vast spectrum from x-rays to radiowaves
Energy can be represented by both:
b. Waves and frequencies