MIDTERM Qs {THE CRUCIAL QUARTER} Flashcards
- An isotope of boron has 5 protons and 6 neutrons. The atomic number of boron is
a. 11
b. 10
c. 6
d. 5
d. 5
- If an electron is gained or lost from an atom, that atom becomes
a. an ion
b. a new element
c. an isotope
d. unstable
a. an ion
- Electric insulators
a. convert electrical energy into heat
b. consist of materials like silicon
c. inhibit movement of electrical charge
d. permit movement of electrical charge
c. inhibit movement of electrical charge
- The electrons in an electrical current
a. all have the same velocity
b. flow from one end of the circuit to another
c. have a net motion in the direction opposite to the conventional current flow
d. none of the above
c. have a net motion in the direction opposite to the conventional current flow
- An induced current in a wire loop
a. results from a constant magnetic flux
b. can result only from an alternatively expanding and contracting magnetic field
c. is in such a direction that its effects oppose the change producing the current
d. always decreases when the magnetic flux decreases
b. can result only from an alternatively expanding and contracting magnetic field
- American generators operate at
a. 220 V
b. 120 AC
c. 60 Hz
d. 30 A
c. 60 Hz
- Backup time
a. cannot exceed the tube limit
b. is not needed for three-phase generators
c. should be set at 150 percent of expected manual mAs
d. both a and c
d. both a and c
- The incoming line current in modern high capacity x-ray units is supplied
a. in the form of a three-phase power cycle
b. in the form of a single-phase power cycle
c. as a direct current
d. at approximately 60 volts
a. in the form of a three-phase power cycle
- Driving the thermionic cloud from the cathode to the anode requires
a. a large potential difference
b. a small voltage
c. a large amperage
d. a small amperage
a. a large potential difference
- The focusing cup has a/an ___ charge.
a. neutral
b. atomic
c. positive
d. negative
d. negative
- The only portion of the anode assembly placed outside the vacuum of the envelope is the
a. stator
b. rotor
c. rotating disc
d. molybdenum neck
a. stator
- The types of target interaction that occur in the production of diagnostic-range x-ray photons are dependent upon
a. electron kinetic energy
b. nuclear binding energy
c. electron potential energy
d. both a and b
d. both a and b
- The quantity of x-rays or gamma rays required to produce a given amount of ionization in a unit mass of air defines the
a. kerma
b. gray
c. roentgen
d. curie
c. roentgen
- The annual effective dose limit for an occupational exposure to ionizing radiation is ___ rem.
a. 1
b. 0.1
c. 5
d. 0.5
c. 5
- Which atomic shell possesses the highest binding energy?
a. K
b. L
c. M
d. all atomic shells possess the same binding energy
a. K
- During the photoelectric interaction, as an electron transfers from an outer shell to a vacant inner shell, energy is released in the form of
a. a characteristic photon
b. a primary radiation
c. an incident electron
d. an incident photon
a. a characteristic photon
- The radiation intensity from a diagnostic x-ray unit will vary in a/an
a. direct relationship with mAs
b. direct relationship with the square of the kVp
c. inverse relationship with the square of the distance
d. all of the above
d. all of the above
- The speed of an imaging system depends on the
a. thickness of the phosphor or silver halide layer
b. crystal/phosphor size
c. efficiency of the crystal/phosphor
d. all of the above
d. all of the above
- The line focus principal allows for a large _______ for maximum heat load and a small ________ for increased detail in an image.
a. effective, actual
b. estimated, actual
c. actual, estimated
d. actual, effective
d. actual, effective
- Photoelectric interactions are __________ related to the Energy of the beam
a. inversely
b. directly
c. inversely cubed
d. directly cubed
c. inversely cubed
