Test Q's: Midterm Review

Question 1

Characteristic K-shell tungsten xrays have an effective energy of what keV?

Answer 1

69 keV

Question 2

Most of the heat generated at the target (anode) is due to what?

a. inner-shell ionization
b. outer–shell excitation
c. nucleus bombardment
d. K x-rays

Answer 2

b. outer-shell excitation

Question 3

Because of the line focus principal, the effective focal spot size decreases with decreasing ..

a. target angle
b. rotor speed
c. window thickness
d. space charge

Answer 3

a. target angle

Question 4

Tube housing of the anode must limit radiation leakage to what?

Answer 4

100 mR/hr @ 1 meter

Question 5

A single-phases waveform has ___ ripple?

Answer 5

100%

Question 6

What is the difference in the waveform between the primary and secondary sides of the high voltage transformer?

Answer 6

Amplitude

Question 7

What are the external structures of the x-ray tube?

Answer 7

• support structure
• protective housing
• glass envelope

Question 8

Voltage across the x-ray tube is most constant with what type of generator?

Answer 8

High frequency generator

Question 9

The quantity of Brem’s radiation increases proportionately with increased ___.

a. kVp
b. mAs
c. filtration
d. rotor speed

Answer 9

b. mAs

Question 10

Changes in ___ result in directly proportional changes in the amplitude of the emission spectrum

a. mA
b. time
c. kVp
d. both A and B

Answer 10

D. both A and B (mAs and time)

Question 11

he cathode side of the tube should be directed toward the ___ part of the patient.

a. thicker
b. upper
c. lower
d. thinner

Answer 11

Thicker

Question 12

A single-phase waveform has ___ ripple

a. 1%
b. 4%
c. 14%
d. 100%

Answer 12

d. 100%

Question 13

Projectile electron travel from ___.

a. anode to cathode
b. cathode to anode
c. target to patient
d. inner shell to outer shell

Answer 13

b. cathode to anode

Question 14

The x-ray generator with the lowest power rating is the ___ imaging system.

a. high frequency
b. three-phase, 12 pulse
c. three-phase, 6 pulse
d. single-phase

Answer 14

d. single phase

Question 15

The ___ of an x-ray beam is higher when the peak of the emission spectrum is further to the ___.

a. quality, right
b. quantity, right
c. quality, left
d. quantity, left

Answer 15

a. quality, right

Question 16

Thermionic emission at the filament creates a ___.

a. space charge
b. grid control
c. line focus
d. heel effect

Answer 16

a. space charge

Question 17

What are the three main parts of the x-ray imaging system?

Answer 17

-the x-ray tube, operating console, and the high voltage generator

Question 18

Characteristic x-rays are produced by___.

a. braking electrons
b. excitation of outer shell electrons
c. nuclear fragmentation
d. released binding energy

Answer 18

d. released binding energy

Question 19

The least accurate type of timer is the____timer

Answer 19

Mechanical timer

Question 20

The efficiency of x-ray production increases as ____ increases.

a. mA
b. kVp
c. time
d. both A and B

Answer 20

b. kVp

Question 21

As an x-ray tube ages, the inside can become coated with tungsten, which can cause ___ in the tube

a. convection
b. anode pitting
c. on-focus radiation
d. arcing

Answer 21

d. arcing

Question 22

an incident xray interacts with an atom without ionization during

Answer 22

Coherent Scattering

Question 23

Only at energies above 10 MeV can ___ take place.

Answer 23

photodisintegration

Question 24

X-rays transmitted without interaction contribute to ___

Answer 24

radiographic image, and is useful information

Question 25

Compton interactions, photoelectric absorption, and transmitted x-rays all contribute to ___

a. patient dose
b. image fog
c. differential absorption (gray vs. black and white)
d. attenuation

Answer 25

c. differential absorption (gray vs. black and white)

Question 26

The light-emitting efficiency (speed) of the intensifying screen is improved by the ___

a. protective coating
b. reflective layer
c. added dyes
d. phosphor afterglow

Answer 26

b. reflective layer

Question 27

Luminescent material emits light after its outer shell electrons are ___.

Answer 27

excited

Question 28

The intensification factor is a measurement of screen ____.

Answer 28

Speed