Electromagnetic Waves

Chapter 5 and 6

Waves

A disturbance in any medium (such as water) which transports energy from one place to another without causing any permanent change in the medium

Transverse waves

Displacement of the medium is perpendicular to the direction of wave travel

Longitudinal or Compressional Waves

Displacement of the medium is parallel to the direction of wave travel

Perpendicular

transverse waves have _________ displacement

Parallel

Longitudinal waves have _______ displacement

water

example of transverse waves

sound waves

examples of longitudinal waves

Speed, Amplitude, Wavelength, Frequency

4 characteristics of all waves

amplitude

The maximum displacement of the medium

strong

amplitude is associated with how ____ the transverse waves are

transverse waves

which waves are specific to x-ray

perpendicularly

transverse waves travel

parallelly

longitudinal waves travel

compression/longitudinal wave

amplitude

displacement can also be referred to as

True

T or F: amplitude can change

transverse waves

1/2

For transverse waves such as water waves, amplitude is _____ of the distance from trough to crest

expansion, compression

For compressional waves such as sound, amplitude is the distance from the middle of an _________ to the middle of a __________

sound waves

example of compressional waves

water waves

example of transverse waves

inverse square law

amplitude follows the

wavelength

Distance measured between two like points along the wave form

prevent it from spreading it

how do you preserve the amplitude of a wave

height/strength

increasing amplitude increases the ____/___ of the wave

crest

top of a wave

trough

bottom of a wave

crest to crest

For transverse waves, _____ to ______, or beginning point to beginning point

middle, middle

For compressional waves such as sound, this is the distance from the _________ of an expansion to the ________ of the next expansion

cycle

One completion of the wave form

pulses

Each cycle consists of two ______, one positive and one negative

cycle

this represents a

circle

For a transverse wave, superimposition of the two pulses creates a

frequency

The number of cycles (waves) that pass by a given point each second

hertz

unit for frequency is

Hz

abbreviation for hertz

speed, or wavelength

Changing the ______ or the _______ will alter the frequency of a series of waves

frequency

increasing the speed increases the

increased

if the wavelength is shortened the frequency is

short

x-rays are short or long waves

wave formula

v = fλ is the

velocity/speed

v represents

frequency

f represents

wavelength

lambda represents

directly proportional

velocity and frequency are _____ _____ to each other in the wave formula

twice

if you are traveling at twice the speed _____ as many waves will strike you per second

no

is velocity constant in the wave formula

directly proportional

velocity and wavelength are ______ _______ to one another in the wave formula

inversly proprtional

frequency and wavelength are ______ _______ to each other in the wave formula

wave formula

this is a mehtod for

waves per second

hertz is defined as

constant

in electromagnetic wave formula v is

3×10^8 m/s

what is the speed of light

c

abbreviation for the speed of light rather than v

same

Differ from water waves in that electromagnetic waves always travel the ____ speed in a vacuum such as outer space

seconds

For electromagnetic waves such as x-rays, unit conversions are often unnecessary because the speed of light is usually given per second and the unit for frequency is Hertz or cycles per second, so the ______ cancel each other out

electromagnetic wave

we utilize which formula in x-ray

Plank Formula

E = hf represents the

A particular shade of green light has a wavelength of 5 X 10-7 meters. How many waves of this green light strike you each second, i.e., what is its frequency in hertz?

0.6 X 1015 Hz

The frequency of red light is 460 trillion cycles per second, or 4.6 X 1014 hertz. What is the wavelength of this electromagnetic wave?

0.65 X 10-6 meters

who is the father of quantum theory

Planck

in Planck’s fomorula, wavelength is _________ _________ to frequency

inversely proportional

energy is represented by

volts

for Planck’s formula the higher the voltage the ________ the wavelength

shorter

the Planck formula relates wavelength to

enery

h x c=

12.4

What is the minimum wavelength of an 80 kVp x-ray beam?

0.15 Angstroms

What is the kV of a single x-ray having a wavelength of 0.2 Angstroms?

62 kV

the ____ __ represents only the shortest wavelength in the beam

peak kV

the peak kV represents the

shortest wavelength

The push and pull of electric charges and magnets are so similar because they are
different manifestations of the same force

electromagnetic force

the x-ray beam is a __________ beam

divergent

polyenergetic means

many energies

the magnetic field is always ____________ to the electrical field

perpendicular

do electrons have to be traveling down a wire in the form of electricity in order to possess a magnetic field

no