chapter 33 Flashcards
give the waves in order of increasing frequency.
smallest:
long waves (10^4)
radio waves (10^11)
microwaves (10^12)
infrared (10^14)
visible spectrum (10^15)
ultraviolet (10^17)
X rays (10^20)
gamma rays
give the waves in order of increasing wavelength.
gamma rays (10^-13)
X rays
ultraviolet
visible spectrum
infreared
microwaves
radio waves
long waves
give the order of increasing wavelength for the visible spectrum.
violent (400 nm)
blue (450 nm)
green (550 nm)
yellow (550-600 nm)
orange (600 nm)
red (600-700)
how do E and B travel in a vacuum?
like electromagnetic waves
do EM waves contain both E and B?
yes, and they are independent
how are plane harmonic EM waves polarized?
linearly polarized
what are plane waves and why are they called that?
- EM waves are in 3D space (not along a line)
- at a given t: E and B are constant for all points with the same x (creates a plane of field at that x)
- every point that has the same x (no matter y, z) have the same electric field
what type of waves are EM waves?
transverse waves, since E and B are perpendicular to the propagation of the wave
how to tell the direction of polarization?
direction of the oscillation for E
what are the possible components for E in plane EM waves?
y and z, since propagation along x, no x component
in plane harmonic waves if E moves along +k, what is the direction of B?
-j, since to get propagation to +i, need -j
in plane waves, is the amplitude of Em constant?
yes
in spherical waves, is the amplitude of Em constant?
no, because the amplitude decreases as the distance becomes greater (when farther away)
at a large distance, spherical waves fronts become like what?
like plane waves
what do EM waves carry?
- energy
- momentum
in linearly polarized EM waves, what is the direction of propagation?
direction of oscillation of E (NOT B)
