Bushong Ch 3 &4
Who first described photons - answer Greeks
Where is electromagnetic energy present - answer everywhere
What are the 4 properties of electromagnetic energy - answer frequency, wavelength,
velocity, and amplitude
Electromagnetic energy exists over a wide range called an - answer energy continuum
Continuum - answeran uninterrupted (continuous) ordered sequence
What was the Greek definition of a photon - answeran atom of light
Quantum - answera small bundle of energy that travels through space at the speed of
light
T/F: an x-ray photon is a quantum of electromagnetic energy - answer true
Who showed that visible light has both electric and magnetic properties - answer James
Clerk Maxwell
What is the current definition of a photon - answeran energy disturbance that moves
through space at the speed of light
What is the speed of light in the SI system of units - answer3x10^8 m/s
What is the speed of light in cm/s - answer3x10^10 cm/s
Photons have no mass and therefore no form, but what do they have - answerelectric
and magnetic fields that are continuously changing in a sinusoidal fashion
What is the term used by physicists to describe interactions among different energies,
forces, or masses that can otherwise be described only mathematically - answerfield
What is the velocity of all electromagnetic radiation - answer3x10^8 m/s (the speed of
light)
Amplitude - answerone-half the range from crest (highest point) to valley (lowest point)
on a sine wave
, What are the important properties of the sine wave model of electromagnetic energy -
answerfrequency (f) and wavelength (represented by Greek letter lambda - upside down
y)
Frequency - answerthe number of wavelengths that pass a set point per second
What unit is frequency measured in - answerhertz (Hz)
What is one Hz equal to - answer1 cycle per second
Wavelength - answerthe distance from one crest to the next crest on a sine wave
frequency and wavelength are ____ (inversely or directly) proportional -
answerinversely (as one gets larger the other gets smaller)
T/F: amplitude is directly related to wavelength and frequency - answerfalse (amplitude
is not related to wavelength or frequency)
What 3 parameters are needed to describe electromagnetic energy - answervelocity,
frequency, and wavelength
What is the wave equation - answera mathematical formula that expresses the
relationship between the 3 parameters of a sine wave
Write out the wave equation - answervelocity = frequency x wavelength (v=f x lambda)
What is the electromagnetic wave equation - answera modification of the wave equation
that takes into account the fact that velocity is always the speed of light
Write out the electromagnetic wave equation - answerc = f x lambda (c=speed of light)
What is the frequency range of electromagnetic energy - answer10^2 to 10^24
What are the photon wavelengths that correspond to the frequency range of
electromagnetic energy - answer10^7 to 10^-16 m
What do you call the entire range of electromagnetic energy - answerthe
electromagnetic spectrum
What 3 regions of the electromagnetic spectrum are most important to radiologic
science - answervisible light, x- and gamma radiation, and RF (radio frequency)
The energy of a photon is ____ (directly or indirectly) proportional to its frequency -
answerdirectly
Who first described photons - answer Greeks
Where is electromagnetic energy present - answer everywhere
What are the 4 properties of electromagnetic energy - answer frequency, wavelength,
velocity, and amplitude
Electromagnetic energy exists over a wide range called an - answer energy continuum
Continuum - answeran uninterrupted (continuous) ordered sequence
What was the Greek definition of a photon - answeran atom of light
Quantum - answera small bundle of energy that travels through space at the speed of
light
T/F: an x-ray photon is a quantum of electromagnetic energy - answer true
Who showed that visible light has both electric and magnetic properties - answer James
Clerk Maxwell
What is the current definition of a photon - answeran energy disturbance that moves
through space at the speed of light
What is the speed of light in the SI system of units - answer3x10^8 m/s
What is the speed of light in cm/s - answer3x10^10 cm/s
Photons have no mass and therefore no form, but what do they have - answerelectric
and magnetic fields that are continuously changing in a sinusoidal fashion
What is the term used by physicists to describe interactions among different energies,
forces, or masses that can otherwise be described only mathematically - answerfield
What is the velocity of all electromagnetic radiation - answer3x10^8 m/s (the speed of
light)
Amplitude - answerone-half the range from crest (highest point) to valley (lowest point)
on a sine wave
, What are the important properties of the sine wave model of electromagnetic energy -
answerfrequency (f) and wavelength (represented by Greek letter lambda - upside down
y)
Frequency - answerthe number of wavelengths that pass a set point per second
What unit is frequency measured in - answerhertz (Hz)
What is one Hz equal to - answer1 cycle per second
Wavelength - answerthe distance from one crest to the next crest on a sine wave
frequency and wavelength are ____ (inversely or directly) proportional -
answerinversely (as one gets larger the other gets smaller)
T/F: amplitude is directly related to wavelength and frequency - answerfalse (amplitude
is not related to wavelength or frequency)
What 3 parameters are needed to describe electromagnetic energy - answervelocity,
frequency, and wavelength
What is the wave equation - answera mathematical formula that expresses the
relationship between the 3 parameters of a sine wave
Write out the wave equation - answervelocity = frequency x wavelength (v=f x lambda)
What is the electromagnetic wave equation - answera modification of the wave equation
that takes into account the fact that velocity is always the speed of light
Write out the electromagnetic wave equation - answerc = f x lambda (c=speed of light)
What is the frequency range of electromagnetic energy - answer10^2 to 10^24
What are the photon wavelengths that correspond to the frequency range of
electromagnetic energy - answer10^7 to 10^-16 m
What do you call the entire range of electromagnetic energy - answerthe
electromagnetic spectrum
What 3 regions of the electromagnetic spectrum are most important to radiologic
science - answervisible light, x- and gamma radiation, and RF (radio frequency)
The energy of a photon is ____ (directly or indirectly) proportional to its frequency -
answerdirectly
