HESI Radiography Practice Test 1 | Exam Already
Graded A+
/. Who discovered x-rays? - Answer-Wilhelm Konrad Roentgen
/.What are 9 characteristics of x-rays? - Answer-1. the ability to penetrate opaque
substances
2. the ability to affect silver halide salts on films in the same manner as light does
3. the ability to stimulate or destroy tissue by ionization
4. they travel at a constant speed, the speed of light
5. they cause fluorescence
6. they are high energy waves
7. they travel as electromagnetic waves or energy
8. they have no mass
9. they travel in a straight line and are invisible
/.What is ionization? - Answer-The production of ions by the removal of electrons from
the atoms of the matter that is struck by the x-rays
/.When does ionization occur? - Answer-whenever x-rays penetrate matter
/.What is an electric current? - Answer-the flow of electrons from one point to another or
through a conductor
/.What is an electric current measured in? - Answer-amperes
/.What is a direct current? - Answer-current flowing in one direction, that is, from positive
and negative. Direct current can be interrupted at certain set intervals
/.What is kilovoltage usually designated as? - Answer-Kilovoltage peak (kVp)
/.What is kilovoltage? - Answer-the measure of the force between the negative cathode
and the positive anode and controls the energy of the electrons striking the tungsten
target.
/.What does kilovoltage control? - Answer-the penetrating ability of the x-rays
/.What is milliamperage? - Answer-the measurement of the quantity or the number of
electrons passing from cathode to anode per second.
/.What does milliamperage have to do with the x-ray beams? - Answer-milliamperage
only deals with the strength of the x-ray beams
, /.What is the maximum permissible dose for occupationally exposed persons? -
Answer-5 rems per year (.1 in one week, 3 rem in any 13 week period)
/.What is the maximum permissible dose formula for occupationally exposed persons? -
Answer-MPD=5rem x (N-18)
/.What does the N stand for in the MPD formula? - Answer-The patients age
/.What does the MPD formula subtract 18 from a person's age? - Answer-because
people 18 years or younger are not supposed to work around x-rays
/.What is erythema? - Answer-a temporary reddening of the skin
/.What is an erythema dose? - Answer-the amount of radiation necessary to produce
erythema
/.What is a lead diaphragm and what is it's purpose in the x-ray cone? - Answer-The
lead diaphragm is a metal disk 0.16 cm thick of lead with a hole in the center. It's
purpose is to collimate or limit the size of the beam of radiation.
/.What is primary radiation? - Answer-radiation coming directly from the target of the x-
ray tube
/.What is secondary radiation - Answer-radiation that is produced whenever x-rays strike
matter.
/.When are secondary x-rays produced? - Answer-when x-rays pass through the tissues
of the face during dental x-ray procedures
/.What primary radiation that has been deviated in direction during passage through a
substance? - Answer-scattered radiation
/.Where does leakage radiation come from? - Answer-May come from the wall of the
tube housing or may come from around the cone
/.What are the 3 important conditions necessary for the production of x-rays? - Answer-
1. a source of electrons (heated filament)
2. a means of accelerating the high speed electrons between one third and one half the
speed of light (a high positive potential)
3. A means of stopping these high-speed electrons suddenly (tungsten target)
/.What is the focal spot of a x-ray tube? - Answer-The small area on the tungsten target
to which the electrons are directed
/.What does a small focal point permit? - Answer-sharper detail on the radiograph
Graded A+
/. Who discovered x-rays? - Answer-Wilhelm Konrad Roentgen
/.What are 9 characteristics of x-rays? - Answer-1. the ability to penetrate opaque
substances
2. the ability to affect silver halide salts on films in the same manner as light does
3. the ability to stimulate or destroy tissue by ionization
4. they travel at a constant speed, the speed of light
5. they cause fluorescence
6. they are high energy waves
7. they travel as electromagnetic waves or energy
8. they have no mass
9. they travel in a straight line and are invisible
/.What is ionization? - Answer-The production of ions by the removal of electrons from
the atoms of the matter that is struck by the x-rays
/.When does ionization occur? - Answer-whenever x-rays penetrate matter
/.What is an electric current? - Answer-the flow of electrons from one point to another or
through a conductor
/.What is an electric current measured in? - Answer-amperes
/.What is a direct current? - Answer-current flowing in one direction, that is, from positive
and negative. Direct current can be interrupted at certain set intervals
/.What is kilovoltage usually designated as? - Answer-Kilovoltage peak (kVp)
/.What is kilovoltage? - Answer-the measure of the force between the negative cathode
and the positive anode and controls the energy of the electrons striking the tungsten
target.
/.What does kilovoltage control? - Answer-the penetrating ability of the x-rays
/.What is milliamperage? - Answer-the measurement of the quantity or the number of
electrons passing from cathode to anode per second.
/.What does milliamperage have to do with the x-ray beams? - Answer-milliamperage
only deals with the strength of the x-ray beams
, /.What is the maximum permissible dose for occupationally exposed persons? -
Answer-5 rems per year (.1 in one week, 3 rem in any 13 week period)
/.What is the maximum permissible dose formula for occupationally exposed persons? -
Answer-MPD=5rem x (N-18)
/.What does the N stand for in the MPD formula? - Answer-The patients age
/.What does the MPD formula subtract 18 from a person's age? - Answer-because
people 18 years or younger are not supposed to work around x-rays
/.What is erythema? - Answer-a temporary reddening of the skin
/.What is an erythema dose? - Answer-the amount of radiation necessary to produce
erythema
/.What is a lead diaphragm and what is it's purpose in the x-ray cone? - Answer-The
lead diaphragm is a metal disk 0.16 cm thick of lead with a hole in the center. It's
purpose is to collimate or limit the size of the beam of radiation.
/.What is primary radiation? - Answer-radiation coming directly from the target of the x-
ray tube
/.What is secondary radiation - Answer-radiation that is produced whenever x-rays strike
matter.
/.When are secondary x-rays produced? - Answer-when x-rays pass through the tissues
of the face during dental x-ray procedures
/.What primary radiation that has been deviated in direction during passage through a
substance? - Answer-scattered radiation
/.Where does leakage radiation come from? - Answer-May come from the wall of the
tube housing or may come from around the cone
/.What are the 3 important conditions necessary for the production of x-rays? - Answer-
1. a source of electrons (heated filament)
2. a means of accelerating the high speed electrons between one third and one half the
speed of light (a high positive potential)
3. A means of stopping these high-speed electrons suddenly (tungsten target)
/.What is the focal spot of a x-ray tube? - Answer-The small area on the tungsten target
to which the electrons are directed
/.What does a small focal point permit? - Answer-sharper detail on the radiograph
