Exposures 2 test 2

The angle on an anode of a x-ray tube helps ensure that more of extra photons produce at the target are

Directed towards the patient

A modern dual focus X-ray tube contains 1 one filament 2 two filament 3 one anode

2 and 3

The anode of a modern rotating in a tube is generally composed of a combination of tungsten, and 1 copper 2 rhenium 3 molybdenum

2 and 3

Vibration of the x-ray tube during a Radiographic exposure will most likely result in 1 an increase in optical density 2 a decrease in radiographic contrast 3 an increase in the amount of focal spot blur

2 and 3

The main function of the Pyrex glass that forms a protective envelope of x-ray tube is 1 the containment of the electron stream near the filament 2 the containment of the vacuum within the x-ray tube 3 the production of the statistic, electrical field around the filament

2 only

The temperature at which thermionic emission occurs is approximately

2200 degrees C

The rotation speed of an anode in most single phase x-ray unit is about

3000 rpm

The major reason that tungsten is the material chosen for the electrodes of a modern x-ray tube. Is it high melting point of about?

3400 degrees

The steepness of the anode angle affect the amount of the 1 anode heal effect 2 field coverage 3 thermionic emission

1 and 2

Which of the following factors will affect size of the focal spot 1 angle of the anode 2 speed of the rotation 3 size of the filament

1 and 3

A reduction in the Kilovoltage, setting during the operation of an x-ray tube will most likely 1 reduce the speed of the electron stream 2 increase the filament temperature 3 decrease the space charge

1 only

Which of the following events occur within the X-ray tube during the exposure (second) stage of the timer mechanism 1 a high potential difference is developed 2 filament heating begins 3 the movement of Bucky grid begins

1 only

If the angle on a x-ray tube, anode is decreased from 12° to 7°. It will result in a decrease in. 1 state of the focal spot 2 loading capacity of the tube 3 field coverage

1, 2, and 3

The maximum anode heat storage capacity of a radiographic tube is related to the type and size of the 1 anode disk 2 thermal cushion 3 external housing

1, 2, and 3

Tungsten is the principal material used in the formation of the 1 surface of the target of a rotating anode 2 surface of the target of a stationary anode old 3 wire used in the helix of the x-ray tube filament

1, 2, and 3

42 induction motor ball bearings 43 anode stem 44 stator windings 45 anode disk 46 tube envelope 47 filament

1, 5, 2, 3, 4, 7

Radiographic examination to require a large tube, current or cereal. Exposures will often play high Speed, rotating anodes with rotational speed of about.

10,000 rpm

The target of a modern rotating, and it is believed, or inclined to an angle of between

10-12 degrees

Which of the following are not an advantage of a rotating type anode tube

A reduction in the amount of low energy photons produced during an exposure

In Order to prevent movement of electrons from the anode during the exposure cycle, the type of current employed for an X-ray tube is

Direct current

The speed and energy of the electron stream as it passes across the x-ray tube is primarily controlled by the

Applied kilovoltage

The filaments in most modern extra tubes are surrounded by metal collar switch serve to

Compress the electron stream

In stationery anode tube, the target is imbedded in an anode made of

Copper

The discovery of x-rays was made by Willhelm ranking in 1895 blocks your meeting with the partially evacuated glass tube called a/an

Crookes tube

The negative electrode of an x-ray tube is commonly called the

Filament

The main reason tungsten is employed as filament material in x-ray tube is its

High melting point

The general formula that is used to determine the ant hill units, created with a fully rectified x-ray tube is

Hu= ma x kv x time

When a radiographer changes from a small to a large focal spot for an exposure, he/she is actually

Selecting a larger filament

The reduction of effective focal spot size from about 2 mm to 1 mm can be accomplished by

Selecting the smaller of the two filaments

The principal method by which the sphere charge can be increased in a mod or tube, is by employing a higher

Mas setting

The line focus principal concerns, the fact of target, angulation and focal spot size. Which is a true statement of this principle.

More than one but not all of above

The majority of heat in a modern rotating in a tube is dissipated through the

Passage of radiant heat to the tube envelope

The ball bearing, which aid in the rotation of the induction motor, require a special vaporizing, lubricating material called

Powered silver

The amount of heat storage capacity of a rotating, and it is not dependent upon which of the following

Prep boost time

The formation of the space charge in a filament of an x-ray tube is accomplished during the of the normal exposure cycle

Prep or boost

The x-ray tube envelope is composed of a heat resistant material called

Pyrex glass

Which is the proper sequence of material transverse by the x-ray beam after leaving the anode of the x-ray tube

Pyrex glass, oil, aluminum

The material that is often added to a rotating anode disk to reduce surface defects and cracks is called

Rhenium

Which of the following portions of induction motor and anode desk assembly of a rotating anode is not normally contain within the vacuum of tube

Stator windings

The temperature of the filament in a modern x-ray tube is most closely related to

The amount of current impressed on the filament

The principal disadvantage of the use of a smaller focal spot during a radiographic exposure is

The limitation of the amount of mass that can be applied to the anode

The durability and efficiency of the tungsten filament is often improved by the addition of the metal

Thorium

The first modern Radiographic tube having a heated filament was originally developed in the early 1900s by

William Coolidge

The thin, flatten surface of the x-ray tube envelope which allows for the minimum absorption of x-rays is term the

X-ray window

The unit of power the watt is derived from the product of

amperage x voltage

In a modern x-ray tube, the positively charged electrode that serves as a target for the electron stream is the

anode disk

In a rotating anode, molybdenum stem is a poor conductor of heat this material helps in preventing

bearing damage of the induction motor

The measurement of the focal spot size and most diagnostic x-ray tubes is based on the computation of the 1 actual focal spot 2 effective focal spot 3electronic focal spot

effective focal spot

Amount of space charge, created at the cathode is primarily controlled by the

impressed amperage

As ma increases, blooming of the focal tract results in a/an

increase in the size of the effective focal spot

In a modern rotating anode, the motion of the rotating disk is accomplished by the use of an

induction motor

The collective repulsion of the electron cloud around the cathode that creates an equilibrium with the rate of electron emission by the filament is termed the

space charge effect

In a modern diagnostic x-ray tube, the majority of the heat that is produced during the x-ray production process is created and concentrated on the

surface of the focal tract

In a modern diagnostic x-ray tube, the vast majority of the energy of the electron stream, striking the target of the anode is converted into

thermal energy (heat) at the surface of the anode

The process by which heating of the filament results in the liberation of electrons in the x-ray tube is called

thermionic emission