# schmucks test #2

what is an atom of light, the smallest quantity of any type of electromagnetic energy, sometimes called a quantum of electromagnetic energy, travels at the speed of light, has no mass and no identifiable form but have electric and magnetic fields photon
what is the number of wavelengths that pass a point of observation per second, the rate of rise and fall, cycles/second, unit of measurement is the Hz, equal to the number of crests or the number of valleys that pass the point of an observer per unit time frequency
what is the distance from one crest to another, from one valley to another or from any point on the sine wave to the next corresponding point, it is represented by the lambda wavelength
what is the electromagnetic wave equation c= f x WL
WL = c/f
what is 1/2 the range from crest to valley over which the sine wave varies, or in simple terms it's the height of the wave amplitude
how do you find the velocity of a wave c=f x WL
what is the velocity of all electromagnetic energy speed of light/ 3×10^8 m/s
what is the reduction in beam intensity due to scattering and absorption attenuation
what is when an object has too few or too many electrons, it is due to the movement of negative electric charge, can be created by contact, friction, or induction electrification
what is the study of electric charges in motion electrodynamics
what is the study of stationary electric charges electrostatics
what is another term for the electrostatic force Coulomb's Law
what law states that the electrostatic force is directly proportional to the product of the electrostatic charges and inversely proportional to the square of the distance between them electrostatic force/Coulomb's Law
what is an example of the electrostatic force when unlike charges are close to each other and the electric fields radiate in the same direction and cause the 2 to attract each other, or vise versa when 2 like charges repel each other… electric field causes attraction/repulsion
what is the formula for electrostatic force F=k (QaQb) / d^2
what is the basis concept of an electron spin electrons have to be rotating on their axis to create a magnetic field
what force is proportional to the product of the magnetic pole strengths divided by the square of the distance between them magnetic force
what is created by an accumulation of many atomic magnets with their dipoles aligned magnetic domain
what is a coil of wire called that's magnetic field is concentrated through the center of the coil, it is a current carrying wire solenoid
what is a coil of wire around an iron/ferromagnetic core that intensifies the induced magnetic field, almost all magnetic field lines concentrated inside the core and escape only near the ends of the coil electromagnet
what is the unit for current A or 1 C/s
what is the unit for electric potential V (volt)
what is the unit for power W (watts)
what is the unit for resistance omega
what is the unit for frequency Hz or 1 cycle/sec
what is the unit for velocity m/s
what is the speed of light 3×10^8
electromagnetic radiation velocity is _____ constant
what is the unit for magnetic field strength T (tessla)
photons have both ____ and _____ properties electric and magnetic
what are the 4 properties of electromagnetic energy frequency, wavelength, velocity, amplitude
photons have no ____ or _____ mass or identifiable form
how are the electric and magnetic fields of photons changing in a sinusoidal fashion
what type of waves are variation of amplitude over time sine waves
name the components of the electromagnetic spectrum from the lowest end to the highest end in order rradiofrequency, microwaves, infared, visible light, UV, gamma rays and X-rays
describe the wavelength going from lowest end of EM spectrum to highest end lower end had a longer WL and higher end has a shorter WL
at a given velocity, wavelength and frequency are ______ proportional inversely
the energy of a photon is ______ proportional to its frequency directly
describe the energy and frequency of the EM spectrum from lowest end to highest end lowest end has low frequency and low energy, higher end has high frequency and high energy
where do X-rays originate from? gamma rays? X-rays are from the electron cloud and gamma rays are from the nucleus
do the differences in frequency and wavelength make a difference in how certain photons interact with matter yes
how do visible light photons tend behave more like a wave than particle
how do X-ray photons tend to behave more like particles than waves
what makes a photons interact w matter more easily when the matter is approx the same size as the photon wavelength
what is wave particle duality when types of photons exhibit both wave and particle behaviors when interacting with matter
all radiation with a wavelength longer than those of radiation interacts with matter primarily as a ______ wave
when visible light interacts with matter, it causes the object's molecules to ______ vibrate
what are the 3 ways visible light can interact w matter transparent, translucent, opaque
what is when light is transmitted thru an object unaltered transparent
what is when light is transmitted thru but scattered and is reduced in intensity translucent
what is when light is totally absorbed by an object opaque
what happens to X-rays when they pass through matter they become attenuated
what does radiopaque mean X-rays were absorbed
what does radiolucent means X-rays pass thru
what law states that radiation intensity is inversely related to the square of the distance from the source inverse square law
I(1)/I(2) = d^2(2)/d^2(1)
of the electromagnetic spectrum, which type of energy can we actually see visible light
electromagnetic energy continuum is ever-present around us and _____ uninterrupted
how are radio waves identified frequency
what unit is radio waves measured in kHz or Hz
radiowaves have very ____ energy and a _____ wavelength low, long
how is visible light identified wavelength
what is the smallest segment of the EM spectrum visible light
visible light has ____ energy and a _____ wavelength low, long
can visible light be refracted yes
how is ionizing radiation identified (X-ray and gamma rays) energy
ionizing radiation has ______ energy than visible light or radio frequency photons more
ionizing radiation has a _____ frequency and _____ wavelength high, short
what is the diagnostic energy range in kVp for ionizing radiation 30-150 kvp
what is the smallest unit of electric charge coulomb or 6.3 x 10^18 electron charges
why do we use the coulomb as the unit of electric charge because the charge of a single electron is too small to be useful
what is electrification when an object has too few or too many electrons, can be created by contact, friction, or induction, DUE TO THE MOVEMENT OF NEGATIVE ELECTRIC CHARGE
do positive charges move at all no
what is electricity movement of electrons
what is an object readily available to take on electric charges, the EARTH is the largest example of this, acts as a reservoir for stray electric charges electric ground
what are the first 2 electrostatic laws 1) unlike charges attract, like charges repel
2) electric charge of a conductor is concentrated along the sharpest curvature of the surface
what are the last 2 electrostatic laws 3) electric charge distribution is uniform throughout or on the surface
4) electrostatic force is directly proportional to the product of the electrostatic charges and inversely proportional to the square of the distance between them
the unit of electric potential is the _____ volt
describe the electrostatic force in simple terms the electrostatic force is very strong when objects are close but decreases rapidly when objects separate, the force of attraction between unlike charges or the repulsion of 2 like charges is attributable to the electric field because it creates a force
when you apply an electric potential to a conductor you get a _____ and a _____ magnetic field and current
the direction of the electric current is ____ the flow of electrons opposite
what law states that the voltage across the total circuit or any portion of the circuit is equal to the current times the resistance ohms law
the manner in which electric currents behave in an electric circuit is described by ohms law
what is ohms law in equation form V = IR
what is an example of an insulator rubber or glass (doesn't permit electron flow, extremely high resistance)
what is an example of a semiconductor silicon or germanium (can be conductive or resistive, basis for computers)
what is an example of a conductor copper or aluminum (variable resistance, obeys ohm's law, requires a voltage)
what is an example of a superconductor niobium or titanium (no resistance to electron flow, no electric potential required, must be very cold)
electric charge of a conductor is concentrated along the _____ curvature of the surface while electric charge distribution is ______ throughout or on the surface of other object sharpest, uniform
what is direct current when electrons flow in one direction along the conductor (battery)
what is alternating current when electrons first flow in one direction, then in another direction, the oscillation is represented by a sine waveform (generator and house appliances)
in the U.S. what standard is there for current 60 Hz = 1 cycle of sine wave completed every 1/60s
any charge in motion produces a ______ due to electrons spinning magnetic field
what is an odd number of electrons called in relation to magnetism magnetic dipole
wbat is the smallest unit of magnetism there isn't one, it can't be broken down any further
what rule describes the direction of the magnetic field compared to the current right hand rule
the direction of the current is ______ to the direction of the magnetic field perpendicular
what circuit has all of the elements connected in a line along the sane conductor series
what circuit contains elements that are connected at their ends rather than lie in a line along the conductor parallel
for s series circuit, give the rule for finding voltage, resistance, and current as it relates to ohms law V = IR, Rtotal = R1 + R2 + R3, Itotal = I1 = I2 = I3, Vtotal = V1 + V2 + V3
for a parallel circuit, give the rule for finding voltage, resistance, and current as it relates to ohms law V = IR, Rtotal = 1/R1 + 1/R2 + 1/R3, Vtotal = V1 = V2 = V3, Itotal = I1 + I2 + I3
what are the 4 magnetic states of matter nonmagnetic, diamagnetic, paramagnetic, ferromagnetic
what are the characteristics of nonmagnetic matter and give examples of it unaffected by a magnetic field, wood and glass
what are the characteristics of diamagnetic matter and give examples weakly repelled from both poles of a magnetic field, water and plastic
what are the characteristics of paramagnetic matter and give examples weakly attracted to both poles of the magnetic field, gadolinium
what are the characteristics of ferromagnetic matter and give examples can be strongly magnetized, iron, nickel, cobalt
every magnetic has ____ poles that contain the strongest magnetic attraction 2
like magnetic poles ____ while unlike magnetic poles ____ repel, attract
the imaginary lines of a magnetic field leave the ____ pole and return to the ____ pole north, south
what is the primary advantage of an electromagnet you can control the intensity/its magnetic field can be adjusted by varying the current through its coil of wire
describe the construction of an electromagnet inside is made up of ferromagnetic material with a coil wrapped around it
electric power is measured in ____ watts
what is the formula for electric power 1 watt = 1 A of current flowing through an electric potential of 1 V… aka P=IV but V=IR so in simple terms P=I^2R
how are magnets classified according to the origin of the magnetic peoperty
what are the 3 magnetic classifications natural (earth), permanent (artificially prod), and electromagnets (electric current conducted through wire to create magnetic field)
what are the 3 magnetic laws 1) every magnet has 2 poles
2) unlike poles attract, like poles repel
3) leave the north, return to the south
what was the voltaic pile constructed of zinc and copper plates
what was the importance of the voltaic pile it led to the invention of the modern day dry cell battery, learned that you could create current
what was Oersted's experiment he set up a compass near a wire and discovered that with an electric current the compass pointed toward the wire… led to discovery that any charge in motion produces a magnetic field
what is faradays law magnitude of induced current depends on
1) strength of magnetic field
2) velocity of magnetic field as it moves past conductor
3) angle of conductor to magnetic field
4) # of turns in conductor
Faraday discovered that an electric current cannot be induced in a circuit merely by the presence of a magnetic field which means the magnetic field cannot be ____ and must be changing constant
what was faradays experiment the magnitude of an induced current depends on 4 factors
what is lenz's law the direction of the induced electric current opposes the action that induces it
what is self induction induction of an opposing voltage in a single coil by its own changing magnetic field
what is mutual induction induction of an alternating current in a secondary coil by supplying an alternating current to the primary coil
an electric generator produces an _____ current alternating
an electric generator turns ____ energy into ____ energy mechanical, electrical
in an electric generator, a coil is placed in between 2 _____ and mechanical energy (hand, steam, water, etc) turns the coil magnets
what is the purpose of a commutator ring in an electric generator it can turn the current produced (alternating) into a direct current
in an electric motor, ____ energy is turned into _____ energy electric, mechanical
in an electric motor, a current is passed thru the wire loop which produces a magnetic field that the wire attempts to ____ itself with but the commutator ring keeps switching to make the wire turn align
what type of motor runs the anode induction motor
how is the induction motor different from an electric motor the induction motor has stators that are placed in a ring around the magnet so it turns in a circle
what is the purpose of a transformer it transforms electric potential and current into higher or lower intensity (changes voltages)
transformers need _____ current alternating
why does a transformer need an alternating current rather than a direct current a direct current applied to the primary coil will induce no current in the secondary coil
what type of transformer is built around a square core of ferromagnetic material with lots of layers, the layering helps reduce energy losses and makes it more efficient closed-core transformer
what type of transformer has an iron core with only one winding of wire that acts as both primary and secondary winding, smaller so restricted to when a small step up or step down in voltage is required, not efficient for X-ray use autotransformer
what type of transformer confines even more of the magnet field lines of the primary winding because the secondary is wrapped around it and there are essentially 2 closed cores, most currently used and most efficient shell type transformer
when you apply a current through the primary coil in a transformer, a current is induced in the ____ coil secondary
what is the transformer law Vs/Vp = Ns/Np
what part of the transformer law is known as the turns ratio Ns/Np
what type of transformer (step up or down) is when the turns ratio is > 1 step up
what type of transformer (step up or down) is when the turns ratio is < 1 step down
in a step up transformer, the voltage is higher on the ____ side than the ____ side secondary, primary
in a step down transformer, the voltage is higher on the _____ side than the ____ side primary, secondary
in a step down transformer, the current on the secondary side is ____ than the primary current larger
in a step up transformer, the current on the secondary side is _____ than the current on the primary side smaller
how is the theory of relativity useful in radiology energy cannot be created or destroyed but it can be transformed
what is planks quantum theory X-rays are created with the speed of light and either exist with velocity c or do not exist at all, the energy of the photon is directly proportional to its frequency (E=hf)