Chapter 01: Introduction to the Imaging Sciences
Johnston/Fauber: Essentials of Radiographic Physics and Imaging, 3rd Edition

MULTIPLE CHOICE

	1.	X-rays were discovered
a.	November 8, 1805	
b.	November 8, 1875	
c.	November 8, 1895	
d.	November 8, 1985	

ANS:	C
X-rays were discovered November 8, 1895.

	2.	Barium platinocyanide was the material in Dr. Roentgen’s laboratory that
a.	covered the cathode ray tube	
b.	fluoresced when the cathode ray tube was energized	
c.	was used to produce the radiograph of Bertha Roentgen’s hand	
d.	protected the people in the room from the x-rays	

ANS:	B
A piece of cardboard covered with barium platinocyanide fluoresced when the tube was energized, leading to further investigation.

	3.	Wilhelm Roentgen’s lab was located in
a.	Wurzburg	
b.	Zurich	
c.	Paris	
d.	Boston	

ANS:	A
Dr. Roentgen’s lab was located at the University of Wurzburg in Wurzburg, Germany.

	4.	The first radiograph produced by Dr. Roentgen was of
a.	his own hand	
b.	his daughter’s hand	
c.	his son’s hand	
d.	his wife’s hand	

ANS:	D
The first radiograph was taken December 22, 1895, of his wife, Bertha’s, hand.

	5.	Exposure times for very early radiographs ranged from
a.	1 second to 5 seconds	
b.	1 minute to 15 minutes	
c.	20 minutes to 2 hours	
d.	2 hours to 5 hours	

ANS:	C
Exposure times for early radiographs took from 20 minutes to 2 hours to produce an image.

	6.	Acute radiodermatitis was
a.	the radiation burn resulting from excessive exposure to x-rays	
b.	common among early patients and operators of x-ray equipment	
c.	a delayed reaction to excessive x-ray exposure	
d.	all of these	

ANS:	D
Early on, the excessive radiation exposure to many operators and patients resulted in radiation burns, a delayed response to the exposure.

	7.	Who brought attention to the dangers of x-rays?
a.	Wilhelm Roentgen.	
b.	Bertha Roentgen.	
c.	Crookes.	
d.	Thomas Edison.	

ANS:	D
Thomas Edison, the famous American inventor, suffered a radiation burn and brought attention to the dangers of x-rays.

	8.	An example of how x-rays were used for entertainment or business gain in a dangerous manner was the
a.	fluoroscopic shoe fitter	
b.	x-ray stove polish	
c.	x-ray headache tablets	
d.	x-ray golf balls	

ANS:	A
Although the stove polish, headache tablets, and golf balls used “x-ray” in their names, the shoe fitter actually exposed shoppers to radiation.

	9.	Mass, length, and time are considered
a.	fundamental quantities	
b.	derived quantities	
c.	radiologic quantities	
d.	none of these	

ANS:	A
Mass, length, and time are the most basic or fundamental quantities.

	10.	Velocity, acceleration, and work are
a.	fundamental quantities	
b.	derived quantities	
c.	radiologic quantities	
d.	none of these	

ANS:	B
Along with force, momentum and power, velocity, acceleration, and work are derived from the fundamental quantities.

	11.	Exposure, dose, and dose equivalent are
a.	fundamental quantities	
b.	derived quantities	
c.	radiologic quantities	
d.	none of these	

ANS:	C
Along with the measure of radioactivity, dose, dose equivalent, and exposure are radiologic quantities.

	12.	The metric system is also known as the
a.	British system	
b.	System International (SI)	
c.	System of Units (SU)	
d.	French system	

ANS:	B
The metric system is also known as the System International (SI).

	13.	In the SI system the unit of measure for mass is
a.	pound	
b.	gram	
c.	kilogram	
d.	ton	

ANS:	C
The SI system uses kilogram to quantify mass.

	14.	In the SI system the unit of measure for length is
a.	meter	
b.	kilometer	
c.	foot	
d.	mile	

ANS:	A
The SI system uses meter to quantify length.

	15.	In the SI system the unit of measure for time is
a.	minute	
b.	second	
c.	hour	
d.	day	

ANS:	B
The SI system uses second to quantify time.

	16.	In the British system the unit of measure for mass is
a.	pound	
b.	gram	
c.	kilogram	
d.	ton	

ANS:	A
The British system uses pound to quantify mass.

	17.	In the British system the unit of measure for length is
a.	meter	
b.	kilometer	
c.	foot	
d.	mile	

ANS:	C
The British system uses foot to quantify length.

	18.	In the British system the unit of measure for time is
a.	minute	
b.	second	
c.	hour	
d.	day	

ANS:	B
The British system uses second to quantify time.

	19.	_______________ is equal to distance traveled divided by the time needed to cover that distance.
a.	Work	
b.	Momentum	
c.	Velocity	
d.	Acceleration	

ANS:	C
Distance traveled divided by the time needed to cover that distance is the formula to derive velocity.

	20.	Meters per second squared (m/s2) is the unit of measure of
a.	velocity	
b.	momentum	
c.	force	
d.	acceleration	

ANS:	D
Meters per second squared (m/s2) is the unit of measure of acceleration.

	21.	Newton is the unit of measure of
a.	velocity	
b.	momentum	
c.	force	
d.	acceleration	

ANS:	C
Force is measured in Newtons.

	22.	Kilograms-meters per second (kg-m/s) is the unit of measure of
a.	velocity	
b.	momentum	
c.	force	
d.	acceleration	

ANS:	B
Kilograms-meters per second (kg-m/s) is the unit of measure of momentum.

	23.	Joule is the unit of measure of
a.	power	
b.	force	
c.	work	
d.	momentum	

ANS:	C
Joule is the unit of measure of work.

	24.	Watt is the unit of measure of
a.	power	
b.	force	
c.	work	
d.	momentum	

ANS:	A
Watt is the unit of measure of power.

	25.	Fd (force ´ distance) is the formula to determine
a.	power	
b.	force	
c.	work	
d.	momentum	

ANS:	C
Fd (force ´ distance) is the formula to determine work.

	26.	Work/time is the formula to determine
a.	power	
b.	force	
c.	work	
d.	momentum	

ANS:	A
Work divided by the time over which it is done (work/t) is the formula for power.

	27.	The formula mv (mass ´ velocity) is used to determine
a.	power	
b.	force	
c.	work	
d.	momentum	

ANS:	D
Mass ´ velocity (mv) is the formula to determine momentum.

	28.	The formula ma (mass ´ acceleration) is for
a.	power	
b.	force	
c.	work	
d.	momentum	

ANS:	B
Mass ´ acceleration (ma) is the formula to determine force.

	29.	What is the velocity of a javelin that travels 45 meters in 3 seconds?
a.	0.067 m/s.	
b.	15 m/s.	
c.	67 m/s.	
d.	135 m/s.	

ANS:	B
Velocity is determined by dividing the distance traveled (45 meters) by the time necessary to cover the distance (3 s); therefore 45 m/3 s or 15 m/s.

	30.	What is the acceleration of the javelin if the initial velocity is 0, the final velocity is 15 m/s and the time of travel is 3 seconds?
a.	1 m/s2.	
b.	5 m/s2.	
c.	10 m/s2.	
d.	15 m/s2.	

ANS:	B
Acceleration is determined by subtracting the initial velocity (0 m/s) from the final velocity (15 m/s) and then dividing that amount by the time it took (3 seconds), resulting in 5 m/s2.

	31.	How much force is needed to move a 30-kg piece of equipment at a rate of 3 m/s2?
a.	10 N.	
b.	30 N.	
c.	60 N.	
d.	90 N.	

ANS:	D
Force is determined by multiplying mass (30 kg) by acceleration (3 m/s2) and is measured in Newtons. 30 kg ´ 3 m/s2 = 90 N.

	32.	What is the momentum of a 30-kg object traveling at 2.5 m/s?
a.	12 kg-m/s.	
b.	75 kg-m/s.	
c.	150 kg-m/s.	
d.	187.5 kg-m/s.	

ANS:	B
Momentum is determined by multiplying mass (30 kg) by its velocity (2.5 m/s), resulting in 75 kg-m/s.

	33.	How much work is done if a force of 20 N is applied to move a patient 100 meters?
a.	0.5 J.	
b.	5 J.	
c.	200 J.	
d.	2000 J.	

ANS:	D
Work = Fd, in this case 20 (force) multiplied by 100 (distance) over which it’s moved, resulting in 2000 Joules.

	34.	If it takes 2 minutes to perform 360 J of work, what is the power?
a.	3 W.	
b.	9 W.	
c.	180 W.	
d.	720 W.	

ANS:	A
Power is determined by dividing the work done (360 J) by the time it takes to do the work (2 minutes or 120 seconds). 360/120 = 3 Watts.

	35.	What is the velocity of a baseball that travels 15 meters in 2 seconds?
a.	7.5 N.	
b.	7.5 m/s2.	
c.	7.5 J.	
d.	7.5 m/s.	

ANS:	D
Velocity is determined by dividing the distance traveled (15 meters) by the time necessary to cover the distance (2 s); therefore 15 m/2 s or 7.5 m/s. The unit of measurement for velocity is meter/second (m/s).

	36.	If a basketball goes from being stationary to a velocity of 18 m/s in 3 seconds, what is its acceleration?
a.	6 N.	
b.	6 m/s2.	
c.	6 m/s.	
d.	6 W.	

ANS:	B
Acceleration is determined by subtracting the initial velocity (0 m/s) from the final velocity (18 m/s) and then dividing that amount by the time it took (3 seconds), resulting in 6 m/s2. The unit of measurement of acceleration is m/s2.

	37.	How much force is needed to move a 20-kg box whose acceleration is 5 m/s2?
a.	100 N.	
b.	100 W.	
c.	100 m/s2.	
d.	100 m/s.	

ANS:	A
Force is determined by multiplying mass (20 kg) by acceleration (5 m/s2) and is measured in Newtons. 20 kg ´ 5 m/s2 = 100 N. The unit of measurement of force is the Newton (N).

	38.	What is the momentum of the 20 kg box that is traveling 10 m/s?
a.	200 m/s2.	
b.	200 W.	
c.	200 kg-m/s.	
d.	200 J.	

ANS:	C
Momentum is determined by multiplying mass (20 kg) by its velocity (10 m/s), resulting in 200 kg-m/s. Momentum is measured in kg-m/s.

	39.	How much work is done if 5 N of force is used to lift a box 3 meters high?
a.	15 W.	
b.	15 kg-m/s.	
c.	15 N/s.	
d.	15 J.	

ANS:	D
Work is determined by multiplying force (5 N) by distance (3 m) over which it’s moved, resulting in 15 Joules. The Joule (J) is the unit of measurement of work.

	40.	If 240 J of work is done in 1 minute, how much power is consumed?
a.	4 J.	
b.	4 W.	
c.	4 kg-m/s.	
d.	4 m/s.	

ANS:	B
Power is determined by dividing the work done (240 J) by the time it takes to do the work (1 minutes or 60 seconds). 240/60 = 4 watts. The unit of measurement of power is the watt (W).

	41.	The property of an object with mass that resists a change in its state of motion is
a.	momentum	
b.	power	
c.	energy	
d.	inertia	

ANS:	D
Inertia is the property of an object with mass that resists a change in its state of motion.

	42.	The principle of inertia was first described by
a.	Wilhelm Conrad Roentgen	
b.	Sir Isaac Newton	
c.	Thomas Alva Edison	
d.	Crookes	

ANS:	B
The principle of inertia was first described by Sir Isaac Newton in the 17th century.

	43.	Newton’s first law of motion states that, unless acted on by an external force, an object at rest
a.	will stay at rest	
b.	will move very slowly	
c.	will accelerate very quickly	
d.	none of these	

ANS:	A
Newton’s first law of motion was that a body at rest will remain at rest unless an external force is applied.

	44.	The ability to do work is
a.	power	
b.	energy	
c.	inertia	
d.	momentum	

ANS:	B
Energy is the ability to do work.

	45.	Energy in a stored state is
a.	kinetic energy	
b.	energy of motion	
c.	potential energy	
d.	power	

ANS:	C
Potential energy is energy in a stored state; it can do work by virtue of position.

	46.	Kinetic energy is
a.	stored energy	
b.	energy being expended	
c.	the same as potential energy	
d.	power	

ANS:	B
Kinetic energy is energy being used or expended.

	47.	Electromagnetic, chemical, electrical, and thermal are all types of
a.	waves	
b.	equipment	
c.	force	
d.	energy	

ANS:	D
Energy comes in many types, including electromagnetic, chemical, electrical, and thermal.

	48.	Einstein’s formula, E = MC2, demonstrates the relationship between
a.	matter and energy	
b.	energy and electricity	
c.	electricity and mass	
d.	mass and electromagnetic energy	

ANS:	A
E = MC2 demonstrates the relationship between matter (M) and energy (E).

	49.	The standard radiologic unit that quantifies radiation intensity is the
a.	rem	
b.	Becquerel	
c.	gray	
d.	roentgen	

ANS:	D
The roentgen quantifies radiation intensity.

	50.	The standard radiologic unit that quantifies the biological effect of radiation on humans and animals is the
a.	Becquerel	
b.	rad	
c.	roentgen	
d.	sievert	

ANS:	B
The rad quantifies the biological effect of radiation on humans and animals.

	51.	The standard radiologic unit that quantifies occupational exposure or dose equivalent is the
a.	rem	
b.	rad	
c.	roentgen	
d.	Becquerel	

ANS:	A
The rem quantifies occupational exposure or dose equivalent.

	52.	The ____________ is the SI unit equivalent to the rad.
a.	rem	
b.	roentgen	
c.	gray	
d.	Becquerel	

ANS:	C
The gray (Gy) is the SI unit equivalent to the rad.

	53.	1 rad = ______________.
a.	10-2 Gy	
b.	10-1 Gy	
c.	10 Gy	
d.	102 Gy	

ANS:	A
One rad is equal to 10-2 Gy or 1/100 Gy.

	54.	1 rem = ______________.
a.	10-2 Sv	
b.	10-1 Sv	
c.	10 Sv	
d.	102 Sv	

ANS:	A
One rem is equal to 10-2 Sv or 1/100 Sv.

	55.	The ____________ is the SI unit equivalent to the rem.
a.	rad	
b.	roentgen	
c.	Becquerel	
d.	sievert	

ANS:	D
The sievert (Sv) is the SI unit equivalent to the rem.

	56.	1 roentgen = ______________.
a.	2.58 ´ 104 C/kg	
b.	2.58 ´ 103 C/kg	
c.	2.58 ´ 10-3 C/kg	
d.	2.58 ´ 10-4 C/kg	

ANS:	D
One roentgen (R) is equal to 2.58 ´ 10-4 C/kg (Coulombs per kilogram).

	57.	The SI radiologic unit that addresses the different biological effects of different types of ionizing radiation is the
a.	rad	
b.	roentgen	
c.	sievert	
d.	gray	

ANS:	C
The sievert/rem addresses the different biological effects of different types of ionizing radiation.

	58.	The shortened form of the standard radiologic quantity curie is
a.	Cr	
b.	Ci	
c.	Ce	
d.	Cu	

ANS:	B
The Ci is the shortened form of curie.

	59.	The ____________ is the SI unit equivalent to the Curie.
a.	roentgen	
b.	becquerel	
c.	sievert	
d.	gray	

ANS:	B
The Becquerel is the SI unit equivalent to the Curie.

	60.	What is the SI equivalent of 3 Ci?
a.	3 Bq.	
b.	111 Bq.	
c.	1.11 ´ 1010.	
d.	1.11 ´ 1011.	

ANS:	D
To convert Curies to Becquerels multiply the Curie value by 3.7 ´ 1010 (37,000,000,000), therefore 3 ´ (3.7 ´ 1010 ) = 1.11 ´ 1011 Bq.

	61.	Which of the following is an expression of the relative risk to humans of exposure to ionizing radiation?
a.	tissue weighting	
b.	effective dose	
c.	dose equivalent	
d.	absorbed dose	

ANS:	B
Effective dose is an expression of the relative risk to humans of exposure to ionizing radiation.

	62.	The tube head assembly consists of
a.	x-ray tube	
b.	tube stand	
c.	collimator	
d.	all of these	

ANS:	D
The tube head assembly consists of the x-ray tube, collimator, and tube stand.

	63.	The positive electrode of the x-ray tube is the
a.	diode	
b.	cathode	
c.	anode	
d.	canode	

ANS:	C
The positive electrode of the x-ray tube is the anode.

	64.	The negative electrode of the x-ray tube is the
a.	diode	
b.	cathode	
c.	anode	
d.	canode	

ANS:	B
The negative electrode of the x-ray tube is the cathode.

	65.	In a typical radiographic room the anode is located
a.	over the head end of the table	
b.	over the foot end of the table	
c.	in the middle of the table	
d.	away from the table	

ANS:	A
In a typical radiographic room the anode is located over the head end of the table.

	66.	To help dissipate the heat produced during x-ray production, the x-ray tube housing is filled with
a.	air	
b.	water	
c.	refrigerant	
d.	oil	

ANS:	D
Oil is found within the tube housing, surrounding the tube, to help dissipate heat.

	67.	The device that restricts the x-ray beam to the area of interest is the
a.	tube housing	
b.	collimator	
c.	mirror	
d.	crosshair	

ANS:	B
The collimator, located beneath the tube housing, restricts the x-ray beam to the area of interest.

	68.	The purpose of the mirror inside the collimator is to
a.	restrict the x-ray beam	
b.	allow the patient to see himself or herself	
c.	focus the x-ray beam	
d.	reflect the light source	

ANS:	D
Located within the collimator, the mirror reflects the light source onto the patient to show the x-ray field size and crosshairs.

	69.	Lead shutters are part of the
a.	tube housing	
b.	tube stand	
c.	collimator	
d.	x-ray tube	

ANS:	C
Adjustable lead shutters are found in the collimator and allow the x-ray beam to be restricted to the anatomic area of interest.

	70.	The floor mount, floor-ceiling mount, and the overhead tube assembly are types of
a.	tube stands or mounts	
b.	x-ray tube designs	
c.	collimator devices	

ANS:	A
The floor mount, floor-ceiling mount, and the overhead tube assembly are types of tube stands or mounts.

	71.	In the hospital setting, the most widely used tube stand or mount is the
a.	floor mount	
b.	floor-ceiling mount	
c.	overhead tube assembly	
d.	under-table tube assembly	

ANS:	C
The most widely used tube stand-mount is the overhead tube assembly because of its versatility.

	72.	The device that is located just under the x-ray table and holds the image receptor in place is the
a.	Bucky assembly	
b.	grid assembly	
c.	floating assembly	
d.	exit assembly	

ANS:	A
The Bucky assembly holds the image receptor in place and also includes a grid.

	73.	Upright radiographic examinations can easily be done with a
a.	floating table	
b.	table Bucky	
c.	fluoroscope	
d.	wall unit	

ANS:	D
The wall unit has a vertical Bucky assembly that makes upright examinations much easier.

	74.	The electricity applied to the tube during x-ray production is controlled at the
a.	tube housing	
b.	collimator	
c.	control panel	
d.	table top	

ANS:	C
Setting the kilovoltage and milliamperage appropriate for the radiographic examination is done at the control panel.

	75.	A radiographic unit that can be taken to the patient’s bedside is considered
a.	mobile equipment	
b.	permanently installed equipment	
c.	bedside equipment	
d.	stationary equipment	

ANS:	A
Mobile equipment is on wheels and can be taken to the patient’s bedside when he or she is too ill to travel to the radiology department.

	76.	What principle articulates the radiographer’s responsibility to minimize radiation exposure to the patient, oneself and others?
a.	ASRT	
b.	ALARA	
c.	ARRT	
d.	HVL	

ANS:	B
It is the radiographer’s responsibility to minimize radiation dose to the patient, oneself, and others in accordance with the As Low As Reasonably Achievable (ALARA) Principle.

	77.	Which of the following is NOT a cardinal principle for minimizing radiation dose?
a.	distance	
b.	shielding	
c.	collimation	
d.	time	

ANS:	C
Central to minimizing radiation dose to oneself and others are the cardinal principles of shielding, time, and distance.

	78.	Which of the following is NOT one of the “tools/tasks” of radiation protection?
a.	decrease collimation	
b.	increase kVp and decrease mAs	
c.	avoid duplicate exams	

ANS:	A
Decreasing the x-ray field size (increased collimation), using higher kVp along with lower mAs, and avoiding duplicate exams are tools/tasks the radiographer can use to minimize patient radiation protection.

TRUE/FALSE

	1.	Mass does not change with gravitational force.

ANS:	T
Although weight is based on the effect of gravitational force, mass is not.

	2.	When 3 kilograms of frozen water is melted, it produces 3 kilograms of water.

ANS:	T
Mass does not change when the substance changes form.

	3.	Weight, measured in pounds, is not affected by gravitational force.

ANS:	F
Weight, as opposed to mass, changes when the gravitational force changes (earth versus moon, for example).

	4.	A floating table top is typical of today’s x-ray tables.

ANS:	T
Today’s x-ray table has a floating table top with electromagnetic locks.

	5.	Permanently installed radiographic equipment can never be replaced because it is permanent.

ANS:	F
Although it is called permanent, this type of equipment can be removed and replaced, but it does take a week or so.

	6.	Screening for pregnancy is not a task the radiographer would perform before a radiographic procedure on a female patient.

ANS:	F
Screening for pregnancy is another important task to minimize unnecessary exposure to a developing fetus.

	7.	Radiographers can develop good work habits by developing a mental checklist for radiographic procedures and performing them the same way every time.

ANS:	T
Radiography is a practice where being a “creature of GOOD habits”—is a good thing. Develop a mental checklist for radiographic procedures and perform them the same way every time.