Chapt 1,Chapt 2, Chapt 3 ,Chapt 4
A 25 watt lightbulb operates on 120-volt household voltage. How much current does the lightbulb draw?
0.21 amp
400 mA is equal to ____________________ amperes.
0.40
Calculate the secondary current that will be induced based on 120 primary turns, 12,000 secondary turns and a primary amperage of 80 A.
0.8
Using an autotransformer, calculate the secondary voltage that will be induced if 220 volts are impressed on the primary side of an autotransformer with 220 total turns when 55 tapped turns are selected.
55 v
calculate the velocity of red light with a wavelength of approximately 4.0 nm (nm = 10^-9) -7.5 x 10^-1 nm/sec -7.5 x 10^18 nm/sec -1.2 x 10^-17 nm/sec -1.2 x 10^1 nm/sec
7.5 x 10^18 nm/sec
21. 74 kV is equal to ____________________ volts.
74,000
an element with an atomic number of 22 has how many electrons in the second principal quantum number level (L shell) -22 -10 -8 -2
8
carbon has an atomic number of 6. one of its isotopes has a mass number of 14. the number of neutrons in this isotope is -6 -8 -14 -19
8
A transformer has 100 primary and 400 secondary turns of wire. What secondary voltage will be induced if 200 volts are placed on the primary coil (assuming no power losses occur)?
800
solenoid
A helix with electrical current
An electron is ___ charged and has a mass of ___ amu -positively; 1 -neutrally; 1 -positively; 0.000548 -negatively; 0.000548
-negatively; 0.000548
Solid state rectifiers use semiconductor technology. This valuable technology has led to the term "Silicon Valley" and is commonly associated with the computer and transistor industries. The core material for semiconductors is silicon which is intentionally combined with impurities using the elements of arsenic, gallium and boron. This process is termed "doping" and is used to control electron flow through an n-p interface or junction. How is arsenic used to affect semiconductor conductance?
Arsenic is an electron contributor through its single valence electron, which forms a covalent bond with silicon. This creates an electron charge carrier that is a better conductor of electron flow than gallium, which creates an electron "hole" as a charge carrier. The doping of silicon with more and more arsenic improves its conductance across the n-p junction.
The design of an x-ray tube requires that electron flow through it is in a single direction or phase. If alternating current were supplied to the x-ray tube at high voltage, what would be the result?
During the negative phase of electron flow, electrons would enter the x-ray tube on the anode side. The design and structure of the anode does not permit thermionic emission. Equally important is that the cathode filament of the cathode assembly is not designed to accept electron bombardment from the anode. If this occurs under high voltage, the cathode assembly would be damaged beyond repair and the tube destroyed.
Photon wavelength is -inversely proportionate to photon velocity -directly proportionate to photon frequency -inversely proportionate to photon frequency -usually designated by the letter c
Inversely proportionate to photon frequency
Current and Numbers
Is Np — = — Ip Ns
The output current in a step-up transformer is:
Lower than the input current
Transformers have iron cores to intensify the:
Magnetic field
V= I x R
Ohm's law
an atom has an atomic number of 18 and a mass number of 38. letting P = the number of protons and N = the number of neutrons, which of the following atoms is the isotope of this atom -P=18, N=20 -P=18, N=21 -P=20, N=18 -none of the above
P=18, N=21
The magnetic flux through a wire loop a. requires a time-varying magnetic field b. is maximum when a plane of the loop is perpendicular to the magnetic field c. increases as the magnetic field decreases d. stays fixed in orientation regardless of electron flow
b. is maximum when a plane of the loop is perpendicular to the magnetic field.
6.24 x 10^18 electrons/sec
ampere
if an electron is gained or lost from an atom, that atom becomes -an ion -a new element -an isotope -unstable
an ion
b. vacuum
an x-ray tube is an example of current flow in a/an: a. gas b. vacuum c. metallic conductor d. ionic solution
The efficiency of a transformer is not affected by
any of the above
an electron doper to improve conductance
arsenic
The orderly arrangements of electrons in the periodic table is based upon -atomic number -atomic mass -mass number -neutron number
atomic number
If the total resistance in a circuit is 9 ohms and the voltage is 3 volts, the current is a. 1/27 ampere b. 1/3 ampere c. 3 amperes d. 27 amperes
b 1/3 ampere
If 10 coulombs pass a point in 2 seconds, the current is a. 0.20 amp b. 5 amps c. 20 amps d. 200 amps
b 5 amps
A simple DC generator has essentially the same construction as an AC generator except that a DC generator employs the use of a. slip rings b. a commutator c. brushes d. an armature
b a commutator
If you purchase four (4) twelve-packs of soda as a fundraiser for $10.00 and sell each can of soda for 50 cents, your profit is a. $9.74. b. $14.00. c. $24.00. d. $34.00.
b. $14.00.
If a transformer is supplied with 16 volts and 4 amperes, the output current from this transformer with an output voltage of 1200 volts would be a. 24 volts b. 0.02 amperes c. 480 amperes d. 800 amperes
b. 0.02 amperes
2.63 10−2 = a. 0.00263 b. 0.0263 c. 26.3 d. 263
b. 0.0263
Convert 87.3% to a decimal. a. 0.0873 b. 0.873 c. 8.73 d. 87.3
b. 0.873
If the intensity of light from a flashlight is 4 millilumens (mlm) at a distance of 3 feet, what will the intensity be at 6 feet? a. 0.4 millilumens b. 1 millilumen c. 2 millilumen d. 16 millilumens
b. 1 millilumen Solve using the inverse square law. I1 = 4 mlm d1 = 3 feet I2 = x mlm d2 = 6 feet 4 / x = (6^2) / (3 ^ 2) 4(3^2) = x(6^2) 36 = 36x 1 = x
The maximum number of electrons that can exist in an electron shell is calculated with the formula _____. Select one: a. 2n b. 2n^2 c. 2/n d. 2/n2
b. 2n^2 pg. 32: maximum number of electrons er shell = 2n^2, where n is the shell number K = 1, L = 2, M = 3, N = 4, O = 5, P = 6, Q = 7
Convert 113°F to °C. a. 20.3°C b. 45°C c. 81°C d. 235°C
b. 45°C
Convert 540.7 to scientific notation. a. 5.407 10^2 b. 5.407 10^−2 c. 5.407 10^3 d. 5.407 10^−3
b. 5.407 10^−2
The inverse of 0.137 is approximately a. 1.37. b. 7.30. c. 73. d. 137.
b. 7.30.
What does ALARA mean? a. All Level Alert Radiation Accident b. As Low As Reasonably Achievable c. Always Leave A Restricted Area d. As Low As Regulations Allow
b. As Low As Reasonably Achievable
The first person to describe an element as being composed of identical atoms was _____. a. J.J. Thomson b. John Dalton c. Dmitri Mendeleev d. Niels Bohr
b. John Dalton pg. 28: according to Dalton, an element was composed of identical atoms that reacted the same way chemically.
Electrical components possess a negative and a positive side. This polarity permits the application of a. resistance across the poles to inhibit electron flow b. an electromotive force (emf) to enable current flow c. a spark gap to check amperage d. all of the above
b. an electromotive force (emf) to enable current flow
An induced current in a wire loop a. results from a constant magnetic flux b. can result only from an alternately 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 alternately expanding and contracting magnetic field
An electrical device that is designed to store charge momentarily after charging is a/an a. battery b. capacitor c. thyristor d. dielectric
b. capacitor
Electric current is defined as a. time/change b. charge/time c. (charge)(time) d. charge/time^2
b. charge/time
Electrons move downward in a vertical wire. The direction of the associated magnetic field directly around the wire is a. clockwise b. counterclockwise c. in the direction of the electron flow d. opposite to the conventional current
b. counterclockwise
The intensity of radiation ______ in ______ proportion to the square of the distance of the object from the source. a. increases, direct b. decreases, direct c. increases, inverse d. decreases, inverse
b. decreases, inverse Pg. 54: the decrease in intensity is inversely proportional to the square of the distance of the object from the source.
The biggest source of man-made ionizing radiation exposure to the public is ______. a. atomic fallout b. diagnostic x-rays c. smoke detectors d. nuclear power plants
b. diagnostic x-rays pg. 6: diagnostic x-rays constitute the largest man-made source of ionizing radiation (3.2 mSv/yr).
A magnetic field is produced by a. electric charges at rest b. electric charges in motion c. permanent magnets only d. electric charges both at rest and in motion
b. electric charges in motion
A magnetic field is produced by a. electric charges at rest b. electric charges in motion c. permanent magnets only d. electric charges both at rest and in motion
b. electric charges in motion
A motor is a device that converts a. thermal energy into electrical energy b. electrical energy into mechanical energy c. electrical energy into electromagnetic energy d. mechanical energy into electrical energy
b. electrical energy into mechanical energy
When the atomic valence and conductance bands overlap a. an insulator is created b. electrical flow easily occurs c. electrical flow is inhibited d. Ohm's law no longer applies
b. electrical flow easily occurs
The rate of rise and fall of a sine wave is called its ______. a. amplitude b. frequency c. wavelength d. velocity
b. frequency pg. 46: the rate of rise and fall is frequency.
The energy of a photon is directly proportional to its _____. a. amplitude b. frequency c. velocity d. wavelength
b. frequency pg. 56: the energy of a photon is directly proportional to its frequency
Conventional current flows a. from cathode to anode b. from anode to cathode c. in either direction d. in the same direction as the electron flow
b. from anode to cathode
If a conductor is positively charged, it a. has too many electrons b. is deficient in electrons c. has more neutrons than electrons d. is deficient in protons
b. is deficient in electrons
Two identical atoms which exist at different energy states are called _____. a. isotopes b. isomers c. isotones d. isobars
b. isomers pg. 36: isomers are identical atoms except that they exist indifferent energy states because of differences in nucleon arrangement.
A moving object has ____ energy. a. potential b. kinetic c. nuclear d. electromagnetic
b. kinetic pg. 4: kinetic energy is the energy of motion.
When an electric current flows through a wire with resistance, energy is a. liberated as x-rays b. liberated as heat c. liberated as light d.absorbed as heat
b. liberated as heat
The magnitude of an induced electromagnetic field depends on what four factors?
the strength of the magnetic field, the speed of the motion between the lines of force and the conductor, the angle between the magnetic lines of force and the conductor, and the number of turns in the conducting coil
b. V
the unit of measure for electric potential is: a. A b. V c. ohm symbol (horseshoe) d. W
according to the "rule of octets" -eight energy levels have electrons -eight protons occupy the outermost shell -the valence shell is chemically inert -both a and c
the valence shell is chemically inert
also called SCR
thyristor
atomic element that creates electron "holes"
gallium
in a vacuum, electromagnetic radiation -has a velocity equal to the speed of light -x-ray energy may be bent by a crystalline lens -causes ionizations of air molecules -is altered by a strong magnetic field
has a velocity equal to the speed of light
Which of the following principles of rectification produces the maximum efficiency of x-ray production?
high frequency
in the excitation process, electrons in an atom are moved to a/an ___ energy state -lower -higher -incomplete -all of the above
higher
a. electrons move on external surface
in a metallic conductor: a. electrons move on external surface b. electrons move internally c. protons move on external surface d. protons move internally
the atomic number is the number of ___ contained in the nucleus -neutrons -electrons -protons -positrons
protons
the nuclear particles that distinguish one element from another are the -neutrons -protons -gamma particles -beta particles
protons
the process by which alternating current is changed to pulsating direct current
rectification
groups of the periodic table -represent elements with the same outer electron configuration -are horizontal -represent elements with the same atomic density -none of the above
represent elements with the same outer electron configuration
resistance to demagnetization
retentivity
a device to control resistance
rheostat
All of the following are true of electromagnetic frequencies except -they are illustrated as sinusoidal waves -they possess both wave and particle characteristics -the relationship between frequency and wavelength is direct and proportional -they are arranged in an orderly spectrum according to frequency and wavelength
the relationship between frequency and wavelength is direct and proportional
b. friction
the removal of electrons from an object by rubbing it with another is electrification by: a. contact b. friction c. induction d. grounding
superconductor
titanium
1,800 /0.30 = a. 0.0001 b. 540 c. 6,000 d. 60,000
c. 6,000
American generators operate at a. 220 V b 120 AC c. 60 Hz d. 30 A
c. 60 Hz
46.3 + 29.87 = a. 245 b. 2,450 c. 76.17 d. 7.617
c. 76.17
For a simple AC generator, the value of the induced voltage in the armature loop is maximum when the orientation of the armature as compared to the magnetic field is a. at a node b. 45 degrees c. 90 degrees d. 180 degrees
c. 90 degrees
The term "atom" was first used by the _____. a. Ethiopians b. British c. Greeks d. Romans
c. Greeks pg. 27: the Greeks used the term atom, meaning "indivisible" [ a (not) + temon (cut) ] to describe the smallest part of the four substances of matter.
The periodic table of the elements was developed by _____ in the late 19th century. a. Bohr b. Rutherford c. Mendeleev d. Roentgen
c. Mendeleev pg. 28: Dmitri Mendeleev showed if the elements were arranged in order of increasing atomic mass, a periodic repetition of similar chemical properties occurred. Mendeleev's work resulted in the first periodic table of the elements.
Ohm's law is mathematically described as a. C=Q/V b. L=-V/It c. R=V/I d. V=I^2R
c. R=V/1
cobalt
ferromagnetic
Parallel resistors of 3 ohms and 6 ohms would result in a total resistance of how many ohms?
2.0 ohms
If a circuit has potential difference of 80 kV and a current of 400 mA, what is the resistance?
2.0 x 10^5 ohms 200,000 ohms
List the 4 Types of Exposure Timers
1. synchronous timers 2. electronic timers 3. mA timers 4. AEC
Calculate the secondary voltage that will be induced based on 10,000 primary turns, 100 secondary turns and a primary voltage of 110 v.
1.1
Using an autotransformer, calculate the secondary voltage that will be induced if 110 volts are impressed on the primary side of an autotransformer with 1000 total turns when 10 tapped turns are selected.
1.1 v
electromagnetic radiation with a frequency of 2,000 hertz would have a wavelength of -1/2,000 cm -1.5 x 10^-7 cm -1.5 x 10^7 cm -cannot be determined
1.5 x 10^7 cm
Calculate the secondary current that will be induced based on 100 primary turns, 10,000 secondary turns and a primary amperage of 1 kA.
10
What is the total resistance of a circuit with two resistances of 3 and 5 ohms in series and two resistances of 4 ohms each in parallel?
10 ohms
Calculate the secondary current that will be induced based on 10,000 primary turns, 100 secondary turns and a primary amperage of 1 A.
100
Using an autotransformer, calculate the secondary voltage that will be induced if 800 volts are impressed on the primary side of an autotransformer with 880 total turns when 110 tapped turns are selected.
100 v
Calculate the secondary voltage that will be induced based on 200 primary turns, 20,000 secondary turns and a primary voltage of 110 v.
11,000
Using an autotransformer, calculate the secondary voltage that will be induced if 440 volts are impressed on the primary side of an autotransformer with 880 total turns when 220 tapped turns are selected.
110 v
A 100 watt lightbulb operates on 120-volt household voltage. How much resistance does the lightbulb offer?
144.6 ohms
Calculate the current supplied to a circuit with two resistances of 3 and 5 ohms in series and two resistances of 4 ohms each in parallel.
2 amperes
Calculate the secondary voltage that will be induced based on 2,000 primary turns, 20,000 secondary turns and a primary voltage of 200 v.
2,000
A transformer has 100 primary and 400 secondary turns of wire. What secondary current (amperage) will be induced if 100 amps are placed on the primary coil (assuming no power losses occur)?
25
Using an autotransformer, calculate the secondary voltage that will be induced if 220 volts are impressed on the primary side of an autotransformer with 400 total turns when 50 tapped turns are selected.
27.5 v
the maximum number of electrons found in any energy level (shell) at any point in time is calculated by the formula -V-I x R -W=F x D -N=amu x Z -2n^2
2n^2
Calculate the secondary voltage that will be induced based on 30,000 primary turns, 300 secondary turns and a primary voltage of 380 v.
3.8
the maximum number of electrons in a period with a principal quantum number of 4 is -6 -8 -18 -32
32
3.7 m are equal to ____________________ cm.
370
If 440 volts are impressed on the primary side of an autotransformer that consists of 110 total turns, what is the secondary voltage that will be induced if the 100th tapped turn is selected?
400 v
An isotope of boron has 5 protons and 6 neutrons. The atomic number of boron is -11 -10 -6 -5
5
if the frequency of a wave is 1,000 hertz and is traveling at 50,000 m/sec, then its wavelength is -0.05 m -0.5 m -5 m -50 m
50 m
A positively charged nucleus surrounded by negatively charged electrons in well-defined orbits is the _____ model of the atom. A) Bohr B) Thomson C) Rutherford D) Dalton
A) Bohr Pg. 29: Bohr improved upon Rutherford's description of the atom. Simply put, the Bohr atom contains a small, dense, positively charged nucleus surrounded by negatively charged electrons that revolve in fixed, well-defined orbits about the nucleus.
An atom that loses or gains one or more electrons is a(n)_____. A) ion B) molecule C) isotope D) isomer
A) ion Pg. 31
The innermost electron shell is symbolized by the letter _____. A) J B) K C) L D) M
B) K Pg. 32: see table 2-2 K = 1, L = 2, M = 3, N = 4, O = 5, P = 6, Q = 7
Rutherford's experiments in 1911 showed that the atom was composed of _____. A) electrons with well-defined orbits B) a nucleus with an electron cloud C) electrified plum pudding D) a ball of hooks and eyes
B) a nucleus with an electron cloud Pg. 29: Ernest Rutherford in 1911 disproved Thomson's model of the atom. Rutherford introduced the nuclear model, which described the atom as containing a small, dense, positively charged center surrounded by a negative cloud of electrons. He called the center of the atom the nucleus.
A difference between self-induction and mutual induction is that:
B. Mutual induction requires two coils and self-induction requires only one.
A charge would lose most of its energy when it passes through: A.battery B.resistor C.generator D.All of the above
B.resistor
diamagnetic
Bismuth
The shell number of an atom is called the _____. A) alpha particle B) chemical element C) principal quantum number D) half-life number
C) principal quantum number Pg. 32: physicists call the shell number n the principal quantum number
The circuit has a current of 2 amperes and a resistance of 4 ohms. The maximum power that can be delivered is a. 16 watts b. 8 watts c. 2 watts d. 1/2 watt
a 16 watts
The current flow from a dry cell battery source would be a. direct current b. alternating current c. variable current d. oscillating current
a direct current
b. vary resistance
a rheostat will: a. provide electric potential b. vary resistance c. increase or decrease voltage d. provide infinite resistance
The material of choice for semiconductors is a. silicon b. carbon c. gadolinium d. ferrous iron
a silicon
In the design of an autotransformer:
a single coil serves as both the primary and the secondary coils
When 6.24 x 10 ^18 electrons travel in one second producing a joule (j) of work, a. one volt has been created b. one ohm has traveled through the circuit c. an ampere of resistance has been generated d. alternating current has been generated.
a. one volt has been created
The smallest quantity of any type of electromagnetic radiation is a(n) _____. a. photon b. electron c. neutrino d. quark
a. photon pg. 45: a photon is the smallest quantity of any type of electromagnetic energy.
The chemical element is determined by the number of _____ in the atom. a. protons b. electrons c. neutrons d. nucleons
a. protons pg. 30: the number of protons determines the chemical element.
A charge would lose most of its energy when it passes through a a. resistor b. battery c. generator d. all of the above
a. resistor
Today, radiology is considered to be a(n) _____ occupation. a. safe b. unsafe c. dangerous d. high-risk
a. safe
Resistance is a. the opposition to the flow of electrons b. the opposition to the generation of electromotive force c. the location of storage of electrons d.measured in amperes
a. the opposition to the flow of electrons
The process of electrons being emitted from heated metallic surfaces is called a. thermionic emission b. electrolysis c. electroplating d. potential difference
a. thermionic emission
When a step-up transformer is in use:
The secondary voltage is greater then the primary voltage.
Volts and Current
Vp Is — = — Vs Ip
Volts and Turns formula
Vs Ns — = — Vp Np
When a step-up transformer is in use
When a step-up transformer is in use
17. The equation (x + y)2 can be expressed as: a. x2 + 2xy + y2 b. 2x + 2y c. x + 2xy + y2 d. x2 + y2 + xy
a. x2 + 2xy + y2
Electromotive force (EMF): a) Is expressed in volts b) Is expressed in joules c) stands for electromagnetic field d) is expressed in farads
a) Is expressed in volts
The term electromagnetic induction refers to the production of: a) an electric current b) electromagnetic radiation c) a static charge d) a magnetic field
a) an electric current
The main advantage of full-wave rectification over half-wave rectification is: a) more x-rays per cycle b) less voltage ripple c) higher-energy x-rays d) higher kVp
a) more x-rays per cycle
Convert 7/12 to a decimal. a. 0.583 b. 1.714 c. 19.83 d. 84.00
a. 0.583
A 100 watt bulb with an amperage of 0.91 A is operating at a potential difference of a. 110 volts b. 100 volts c. 11 kilovolts d. 110 ohms
a. 110 volts
Aluminum has an atomic number of 13. How many protons does it have? a. 13 b. 26 c. 27 d. none of the
a. 13 Pg. 34: the number of protons is called the atomic number, represented by "Z"
16.3 x 1.2 = a. 19.56 b. 195.6 c. 17.5 d. 1.75
a. 19.56
The diagnostic range of x-ray energy is _____. a. 30 to 150 kVp b. 200 to 300 kVp c. 300 to 1000 kVp d. over 1 MV
a. 30 to 150 kVp
Coulomb's law of electrical forces is mathematically described as a. F=q1q2/r^2 b. F=q/r^2 c. F=q1q2/r d. F=q2/r
a. F=q1q2/r^2
Filtration is used to _________. a. absorb low-energy x-rays b. remove high-energy x-rays c. restrict the useful beam to the body part imaged d. fabricat gonadal shields
a. absorb low-energy x-rays pg. 12: metal filters, usually aluminum or copper, are inserted into the X-ray tube housing so that low energy x-rays are absorbed before they reach the patient.
A semiconductor diode: a. allows current to flow only from n-type of material to p-type b. allows current to flow only from p-type of material to n-type c. contains carriers that are also called proton traps d. contains holes that are also called proton trapse. is also called an electromechanical rectifier
a. allows current to flow only from n-type of material to p-type
An autotransformer
a. contains a single coil that serves as both primary and secondary coils
If the distance between two electrical charges is doubled, the force between them is a. decreased by 1/4 b. decreased by 1/2 c. doubled d. quadrupled
a. decreased by 1/4
The resistance in a wire decreases as its a. diameter increases b. diameter decreases c. temperature increases d. surface area decreases
a. diameter increases
During beta emission, an atom releases _____. Select one: a. electrons b. positrons c. protons d. neutrons
a. electrons pg. 37: during beta emission, an electron created in the nucleus is ejected from the nucleus with considerable kinetic energy and escapees from the atom.
X-rays are usually identified by their ______ . a. energy b. velocity c. wavelength d. hertz
a. energy pg. 51: Visible Light = identified by wavelength (measured in nanometers, nm) RF = identified by frequency (measured in hertz, Hz) X-rays = identified by energy (measured in electron voltes, eV)
Photons tend to interact with matter____ their wavelength. a. equal in size to b. larger in size than c. smaller in size than d. unequal in size to
a. equal in size to pg. 51: photons interact with matter most easily when the matter is approximately the same size as the photon wavelength.
A transformer with more secondary windings than primary windings a. has a greater secondary voltage b. is a step-down transformer c. has a greater power output than input d. has a higher power loss
a. has a greater secondary voltage
Neon lights illustrate the fact that electrons will flow a. in a gaseous environment b. in a vacuum c. in an ionic solution d. in a solid conductor
a. in a gaseous environment
What is the removal of an electron from an atom called? a. ionization b. pair production c. irradiation d. electricity
a. ionization pg. 5: ionizing radiation is any type of radiation that is capable of removing an orbital electron from the atom with which it interacts (ionization)
The inherent power loss of electrical conduction through solid wire conductors a. is minimized with higher voltage transmission b. has no relationship with current flow c. results from space charge d. is lower with current flow rather than electron flow
a. is minimized with higher voltage transmission
Matter is measured in_____ a. kilograms b. joules c. electron volts d. rems
a. kilograms pg. 3: matter is anything that occupies space and has mass. Mass is measured in kilograms.
Ice and steam are examples of two forms of ______ a. matter b. radiation c. energy d. work
a. matter pg. 4: matter can be transformed from one size, shape, and form to another.
An ampere is a. coulomb/sec. b. (coulomb)(sec). c. (volt)(ohm) d. ohm/volt
a.coulomb/sec
1/6 4/5 = a. 1/5 b. 4/11 c. 5/24 d. 4/30
c. 5/24
The basic quantities measured in mechanics are ____, ____, and _____. a. volume, length, meters b. mass, length, time c. radioactivity, dose, exposure d. meters, kilos, seconds
b. mass, length, time pg. 12: only three measurable quantities are considered basic. These base quantities are mass, length, and time, and they are the building blocks of all other quantities.
A chemical compound is any quantity of _____. a. one type of atom b. one type of molecule c. two types of molecules d. two or more types of atoms
b. one type of molecule Pg. 36: The smallest particle of an element is an atom. The smallest particle of a compound is a molecule. Atoms of various elements may combine to form molecules. A chemical compound is any quantity of one type of molecule.
The lowest energy range of the electromagnetic spectrum is _______. a. sound waves b. radio waves c. gamma rays d. microwaves
b. radio waves pg. 49: see figure 3-6
The number of significant digits in 3.75 104 is a. two. b. three. c. four. d. five.
b. three.
The _______ of electromagnetic radiation is constant. a. amplitude b. velocity c. frequency d. wavelength
b. velocity pg. 47: velocity is constant
An example of a derived quantity in mechanical physics is a _______ a. meter b. second c. dose d. volume
b. volume pg. 12: derived quantities are derived from a combination of one or more of the three base quantities. For example, volume is length cubed. Derived quantities = energy, power, work, momentum, force, velocity, acceleration.
An atom in a normal state has an electrical charge of _____. a. one b. zero c. positive d. negative
b. zero pg. 31: in their normal state atoms are electrically neutral; the electric charge on the atom is zero.
Which of the following would likey be classified as ferromagnetic material? a) lead b) air c) iron d) glass
c) iron
An electromagnet: a) cannot be turned off b) produces a magnetic field with or without an electric current c) is a coil of wire wound around an iron core d) has an air core
c) is a coil of wire wound around an iron core
The magnetic field produced by an electromagnet has: a) only a south pole b) alternating poles c) properties similar to a bar magnet d) only a north pole
c) properties similar to a bar magnet
Computed tomography was developed in the _____. a. 1890's b. 1920's c. 1970's d. 1990's
c. 1970's pg. 10: positron emission tomography and CT were developed in the 1970's.
In the United States, we are exposed to ______ mR/year of ionizing radiation from the natural environment. a. 0-5 b. 5-20 c. 20-90 d. 100-300
c. 20-90
What is the velocity of all electromagnetic radiation? a. 8 x 10^3 m/s b. 2 x 10^8 m/s c. 3 x 10^8 m/s d. 4 x 10^3 m/s
c. 3 x 10^8 m/s pg. 45: the velocity of all electromagnetic radiation is 3 x 10^8 m/s
If 20 volts of potential difference causes a current of 5 amperes to flow in a parallel circuit, the resistance produced is a. 1/100 ohm b. 1/4 ohm c. 4 ohms d. 100 ohms
c. 4 ohms
1/7 + 5/9 = a. 6/16 b. 35/63 c. 44/63 d. 9/35
c. 44/63
All of the following are true of induction motors EXCEPT a. They use multiphase current and can turn at varying rpm b. Motor power can be regulated by the characteristics of the electromagnets that make up the stator. c. Their design is inherently weak with regard to power d. They are used to spin the x-ray tube anode disk
c. Their design is inherently weak with regard to power
The atomic number of an element is symbolized by the letter _____. a. A b. X c. Z d. n
c. Z Pg. 34: the number of protons is called the atomic number, represented by "Z"
The reduction of radiation intensity due to scattering and absorption is called ______. a. reflection b. refraction c. attenuation d. dispersion
c. attenuation pg. 616: see glossary
What is the electromagnetic wave equation? a. c = fλ b. c = f/λ c. c = fv d. c = f - λ
c. c = fλ pg. 48: c = fλ, f = c/λ, λ = c/f
All of the following choices are considered good metallic electrical conductors EXCEPT a. gold b. silver c. carbon d. copper
c. carbon
The milliampere (mA) is a unit of a. EMF b. voltage c. current d. potential difference
c. current
If the wavelength of a beam of electromagnetic radiation increases by a factor 2, then its frequency must ________. a. double b. increase four times c. decrease by half d. remain constant
c. decrease by half Pg. 47: frequency and wavelength are inversely proportional, so as wavelength increases by a factor of two (2/1), frequency decreases proportionately (1/2).
Ionizing radiation is capable of removing _____ from atoms as it passes through the matter. a. neutrons b. protons c. electrons d. ions
c. electrons pg. 5: ionizing radiation is any type of radiation that is capable of removing an orbital electron from the atom with which it interacts (ionization)
The four properties of photons are _____, ______, _____, and _____. a. size, shape, spin, mass b. frequency, mass, amplitude, wavelength c. frequency, wavelength, velocity, amplitude d. refraction, velocity, spin, amplitude
c. frequency, wavelength, velocity, amplitude pg. 58: frequency, wavelength, velocity, and amplitude are used to describe the various imaging regions of the electromagnetic spectrum.
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
A semiconductor
c. is a solid state device
Atoms and molecules are the fundamental building blocks of: a. energy b. radiation c. matter d. gravity
c. matter pg. 3: the fundamental complex building blocks of matter are atoms and molecules.
A generator is a device that converts a. electrical energy to thermal energy b. thermal energy to electrical energy c. mechanical energy to electrical energy d. electrical energy to mechanical energy
c. mechanical energy to electrical energy
When atoms of various elements combine, they form _____. a. isotopes b. compounds c. molecules d. ions
c. molecules pg. 36: atoms of various elements may combine to form structures called molecules.
The charge carriers are considered to be a negative in a/an a. diode b. triode c. n-type semiconductor d. p-type semiconductor
c. n-type semiconductor
The formula E=mc^2 is the basis for the theory that led to the development of____ a. x-rays b. electromagnetic radiation c. nuclear power d. cathode ray tubes
c. nuclear power pg. 5: this mass-energy equivalence serves as the basis for the atomic bomb, nuclear power plants, and certain nuclear medicine imaging modalities.
Gamma rays are produced in the ____ of the atom. a. outer electron shell b. inner electron shell c. nucleus d. K-shell
c. nucleus pg. 51: gamma rays come from the inside of the nucleus of radioactive atoms.
The turns ratio of a transformer is determined by the a. size of the wire b. type of wire c. number of windings d. space between the transformer sides
c. number of windings
The only difference between x-rays and gamma rays is their _____. a. energy b. size c. origin d. name
c. origin PG. 42: the only difference between x-rays and gamma rays is their origin. Gamma rays are emitted from the nucleus of a radioisotope and are usually associated with alpha or beta emission. X-rays are produced outside the nucleus in the electron shells.
______ is a special quantity of radiologic science. a. mass b. velocity c. radioactivity d. momentum
c. radioactivity pg. 14: special quantities are designed to support measurement in specialized areas of science. In radiologic science, special quantities are those of exposure, dose, effective dose, and radioactivity.
The mass equivalent of a 100 KeV photon of radiation can be calculated using the _______. a. inverse square formula b. equivalent Planck equation c. relativity formula d. Planck quantum equation
c. relativity formula pg. 57: Einstein's mass-energy equivalence equation (E=mc^2) —> allows the calculation of energy equivalence of mass and mass equivalence of energy.
The binding energies, or energy levels, of electrons are represented by their _____. Select one: a. atomic numbers b. atomic mass units c. shells d. isotopes
c. shells pg. 31: Electrons can exists only in certain, which represent different electron binding energies.
In a parallel circuit, a. Ohm's law does not apply b. total current flow is equal across its parallel branches c. the voltage is equal across all branches of the circuit d. as more resistors are added total resistance increases
c. the voltage is equal across all branches of the circuit
All of the following are true of transformers EXCEPT a. They have no moving parts b. They work on the principle of mutual induction c. They work most efficiently on pulsating DC d. They are designed
c. they work most efficiently on pulsating DC
Electric potential is measured in a. coulombs b. joules c. volts d. ohms
c. volts
a device capable of accumulating and storing an electrical charge
capacitor
The magnetic field produced: a) By Ac is stronger than that produced by DC b) By an AC source is constant c) By a solenoid is more intense than that produced by an electromagnet d) In a transformer is based on mutual induction
d) In a transformer is based on mutual induction
Which of the following is a transformer design used in x-ray imaging? a) Capacitor type b) Rectifier type c) Filament type d) Shell type
d) Shell type
A hertz (Hz) is equal to _____ cycle(s) per second. a. 103 b. 102 c. 10 d. 1
d. 1 pg. 46: 1 hertz is equal to 1 cycle per second.
15. Mercury (Hg), a metal, is liquid at room temperature. Its density is 13.6 g/cm3. If you have 100 mL of Hg, how many grams do you have? a. 0.136 b. 1.36 10^−3 c. 136 d. 1.36 10^3
d. 1.36 10^3
A current of 2 amperes and a resistance of 8 ohms require what voltage in a series circuit? a. 1/16 volt b. 1/4 volt c. 4 volts d. 16 volts
d. 16 volts
Change 23.46 to a percent. a. 0.2346% b. 23.46% c. 2.346% d. 2,346%
d. 2,346%
5/8 7/9 = a. 12/17 b. 45/56 c. 12/72 d. 35/72
d. 35/72
The atomic number of molybdenum is 42 and the atomic mass number is 98. How many neutrons does it have? a. 42 b. 98 c. 21 d. 56
d. 56 Pg. 34: the number of protons plus the number of neutrons in the nucleus of an atom is called the atomic mass number ("A") atomic mass - atomic number = neutrons
How many times does and AC current change direction in a single minute? a. 30 b. 60 c. 120 d. 7,200
d. 7,200
Energy is measured in: a. Kilograms b. joules c. electron volts d. B or C
d. B or C Pg. 4: energy is measured in joules (J). In radiology the electron volt (eV) is often used.
All of the following are true of autotransformers EXCEPT: a. They are considered a variable transformer b. The primary and secondary coils are in series c. The primary and secondary windings share a common coil d. They are effective in controlling voltage on the high voltage side of the circuit
d. They are effective in controlling voltage on the high voltage side of the circuit
The _____ is the least penetrating form of ionizing radiation. a. beta particle b. x-ray c. gamma ray d. alpha particle
d. alpha particle pg. 41: the energy of an alpha particle is quickly lost. It has a very short range in matter. Consequently, alpha radiation from an external source is nearly harmless because the radiation energy is deposited in the superficial layers of the skin.
The smallest particle that has all the properties of an element is a(n) _____. a. neutron b. proton c. electron d. atom
d. atom pg. 27: the atom is the smallest particle of matter that has the properties of an element.
When using alternating current, a. resistance is calculated as impedance (Z) b. electrical production can be graphically expressed as a sinusoidal wave. c. it must be rectified prior to the high voltage transformer. d. both a and b
d. both a and b resistance is calculated as impedance (Z) electrical production can be graphically expressed as a sinusoidal wave.
A diode electron tube such as a valve tube a. is used for amplification b. has a negatively charged anode c. is used to vary the primary voltage d. can be used for rectification
d. can be used for rectification
A diode electron tube such as a valve tube a. is used for amplification b. has a negatively charged anode c. is used to vary the primary voltage d. can be used for rectification
d. can be used for rectification
A rectifier a. refers to a type of electromagnetic device b. changes electron flow to current flow c. converts DC to AC d. converts AC to DC
d. converts AC to DC
Radio waves, light, and x-rays are all examples of _____ energy: a. nuclear b. thermal c. electrical d. electromagnetic
d. electromagnetic pg. 4: In addition to x-rays and gamma rays, electromagnetic energy includes radio waves; microwaves; and ultraviolet, infrared, and visible light.
The energy of x-rays is _______ a. thermal b. potential c. kinetic d. electromagnetic
d. electromagnetic pg. 4: In addition to x-rays and gamma rays, electromagnetic energy includes radio waves; microwaves; and ultraviolet, infrared, and visible light.
A stator consists of a. bars of copper around an iron core b. commutator rings c. a rotor d. electromagnets
d. electromagnets
Exposure is measured in units of ______ a. becquerel b. sieverts c. meters d. grays
d. grays pg. 22: the SI unit of air Kerma (mGy) is used to express radiation exposure.
If a DC circuit is a. in series, the currents are different for each component (e.g., resistors). b. in series, the voltages are the same for each component. c. in parallel, the currents are equal for all paths of the circuit d. in parallel, the voltages are equal for all paths of the circuit.
d. in parallel, the voltages are equal for all paths of the circuit.
which of the following is not a basic characteristic of the wave equation -velocity -wavelength -frequency -energy
energy
The intensity of radiation on an object is reduced with distance because the radiation _______. a. reduces its veloctiy b. increases in wavelength c. loses it energy d. is spread out over a greater area
d. is spread out over a greater area pg. 54: the reason for the rapid decrease in intensity with increasing distance is that the total light emitted is spread out over an increasingly larger area.
When an atom has the same number of protons as another, but a different number of neutrons, it is called an _____. a. isomer b. isobar c. isotone d. isotope
d. isotope pg. 35: isotopes of a given element contain the same number of protons, but varying numbers of neutrons.
An alternately expanding and contracting magnetic field is produced by
d. none of the above
An alternately expanding and contracting magnetic field is produced by a. a stationary magnet b. a steady current flowing in a wire c. a battery d. none of the above.
d. none of the above
In a battery circuit with several resistors of different values connected in series, a. the voltage drop is the same across all the resistors b. the current through each resistor is different c. the power dissipated through each resistor is the same d. none of the above.
d. none of the above
What are the fundamental particles of an atom? a. quark, positron, negatron b. nucleon, electron, proton c. proton, neutron, quark d. proton, electron, neutron
d. proton, electron, neutron pg. 29: the fundamental particles of an atom are the electron, proton, and the neutron.
A neutral atom has the same number of _____ and electrons. a. quarks b. neutrinos c. neutrons d. protons
d. protons pg. 31: in their normal state atoms are electrically neutral; the electric charge on the atom is zero.
Photons with the highest frequencies have the ______. a. highest velocity b. lowest energy c. longest wavelengths d. shortest wavelengths
d. shortest wavelengths pg. 52: the shorter the photon wavelength the higher the photon energy
The efficiency of a transformer is not affected by a. eddy current loss b. power loss c. hysteresis loss d. the transformer turns ratio
d. the transformer turns ratio
The charge on each of two objects is doubled, and they are moved twice as far apart. The force between them is a. increased by a factor of 4 b. increased by a factor of 2 c. increased by a factor of 1/2 d. unchanged
d. unchanged
The unit of electrical power is a. joule b. volt c. ampere d. watt
d. watt
A bar magnet and a wire loop move with the same linear velocity and direction. What is the voltage induced in the wire? a. maximum when the wire and magnetic flux are parallel b. directly proportional to their velocities c. inversely proportional to the velocities d. zero
d. zero
The magnitude of force felt by a moving charge through a magnetic field would be LEAST if the charge were a. moving directly into the magnetic field b. moving directly away from the magnetic field c. moving at a right angle to the magnetic field d. both a and b
d.both a and b moving directly into the magnetic field and moving directly away from the magnetic field
A step-up transformer results in
decreased current ,increased voltage
Isotopes have ____ mass numbers and ____ atomic numbers. -the same; the same -the same; different -different; the same -different; different
different; the same
designed to permit electron flow in one direction only
diode
The main advantage of full-wave rectification over half-wave rectification is: a. higher-energy x-rays b. higher kVp c. higher mA d. less voltage ripple e. more x-rays per cycle
e. more x-rays per cycle
receiving an electrical shock from touching a doorknob
electrification by contact
the production of lighting
electrification by induction
electrical coil with ferrous core
electromagnet
a stator consists of
electromagnets
a wide band gap
insulator
when comparing iodine (Z=53) with barium (Z=56), -barium has a lower k-shell binding energy -iodine has more neutrons -iodine has five (5) orbitals with electrons -barium has fewer protons
iodine has five (5) orbitals with electrons
all of the following are true of the substance glucose except -the smallest subdivision of this molecule is glucose -it is a compound -it consists of three elements -it may be broken down into one atom of glucose
it may be broken down into one atom of glucose
The unit of mass is the -m/sec -mm -kg -cc
kg
ratio between field strength and area
magnetic flux
c. curved lines of force in space
magnetic flux is: a. magnetic material b. groups of smaller magnets c. curved lines of force in space d. the magnetizing of other materials
the sum of protons and neutrons in a nucleus is called the -electron number -atomic weight -quantum number -mass number
mass number
List the three ways to induce an electromagnetic field
move the conductor through a magnetic field, move the magnetic field across a stationary conductor, and vary the magnetic field strength across a stationary conductor
b. negative charges
nearly all discussion of electricity deals with the movement of: a. positive charges b. negative charges c. neutrons d. all of the above
During half-wave rectification, which side is suppressed? a) positive b) negative c) both sides d) neither side
negative
I t=I 1 +I 2 +I 3 + I n
parallel circuit
materials that have a low permeability and weak attraction to magnetic fields(aluminum)
paramagnetic
Z = 32
semiconductor
p-type material sandwiched with n-type material
semiconductor
silicon
semiconductor
10V + 5V + 12V + 3V = 30V
series circuit
a coil consisting of a series of loops, which serve to increase the flux density
solenoid
all of the following are energy forms except -sound -thermal -electrical -nuclear
sound
electron rotation on an axis
spin magnetic moment
quarks may behave according to the ___ theory -string -quantum -relativity -electromagnetic
string
10,000 gauss
tesla
The transformer changes:
the amplitude of the voltage
b. volt
the potential difference that will maintain a current of 1 ampere in a circuit with a resistance of 1 ohm is the definition of: a. ampere b. volt c. ohm d. coulomb
a period in the periodic table is -represented by a column -vertical -the principal quantum number -determined by the valence electrons
the principal quantum number
obsolete type of rectification technology
valve tube
an expression of electrical power
watt (W)
If the photon frequency of electromagnetic radiation is increased tenfold, then the -velocity will increase times 10 -velocity will decrease to 10 -wavelength will increase times 10 -wavelength will decrease to 1/10
wavelength will decrease to 1/10
c. paramagnetic
what is the magnetic classification of materials weakly attracted to magnets? a. nonmagnetic b. ferromagnetic c. paramagnetic d. no such classification
d. diode
which of the following allows electrons to flow in only one direction? a. transformer b. rheostat c. battery d. diode
c. large cross-sectional area
which of the following conditions or environments will provide the least resistance? a. glass material b. long conductor c. large cross-sectional area d. high temperature of conductor
d. transformer
which of the following increases or decreases voltage by a fixed amount? a. capacitor b. rheostat c. diode d. transformer
a. ampere
which of the following is a unit of measure of current? a. ampere b. volt c. coulomb d. ohm
b. electrostatic force between charges is directly proportional to product of quantities and inversely proportional to square of distance between them
which of the following is coulomb's law? a. like charges repel, unlike charges attract b. electrostatic force between charges is directly proportional to product of quantities and inversely proportional to square of distance between them c. electric charges reside only on the external surface of conductors d. only positive charges can move in solid conductors
