Chapter 24

Question 1

a conduction current is carried by ___________

Answer 1

charged particles in a wire

Question 2

ampere’s law is only valid if the ___________ is ___________ in space

Answer 2

conduction current

continuous

Question 3

magnetic fields are produced by both: ___________ and ___________

Answer 3

conduction currents

changing electric fields

Question 4

the displacement current (Id) is equal to the ___________ in the wires connected to the capacitor

Answer 4

conduction current (I)

Question 5

gauss’s law relates an ___________ to the ______________________

Answer 5

electric field

charge distribution that creates it

Question 6

the number of ___________ that enter a closed volume must equal the number that ___________ that volume

Answer 6

magnetic field lines

leave

Question 7

faraday’s law of induction describes the creation of an ___________ by a changing ___________

Answer 7

electric field

magnetic flux

Question 8

the emf equals the rate of change of ___________ through any surface ___________ by that path

Answer 8

magnetic flux

bounded

Question 9

one consequence of faraday’s law is the ___________ induced in a conducting loop placed in a time- varying ___________

Answer 9

current

magnetic field

Question 10

ampere-maxwell law describes the creation of a ___________ by a changing ___________ and by ___________

Answer 10

magnetic field
electric field
electric current

Question 11

electromagnetic waves move at the ___________. light waves are a form of ___________.

Answer 11

speed of light

electromagnetic radiation

Question 12

an electromagnetic wave consists of ___________ and ___________. the changing fields induce each other, which maintains the ___________ of the wave.

Answer 12

oscillating electric
magnetic fields
propagation

Question 13

a ___________ induces a magnetic field

Answer 13

changing electric field

Question 14

a ___________ induces an electric field

Answer 14

changing magnetic field

Question 15

the electric and magnetic fields are mutually ___________. the direction of the propagation is the direction of the ___________.

Answer 15

perpendicular

vector product, E x B

Question 16

at every instant, the ratio of the magnitude of the ___________ to the magnitude of the ___________ in an electromagnetic wave equals the ___________

Answer 16

electric field
magnetic field
speed of light

Question 17

electromagnetic waves ___________ the superposition principle because the differential equations involved E and B are ___________.

Answer 17

obey

linear equations

Question 18

light exhibits a ___________

Answer 18

doppler effect

Question 19

doppler effect is an apparent change in ___________ due to the ___________ of an observer or the source

Answer 19

frequency

motion

Question 20

light emitted by atoms are normally found in the ___________ of the spectrum is shifted toward the ___________ of the spectrum for atoms in other galaxies

Answer 20

extreme violet region

red end

Question 21

electromagnetic waves carry ________ and as they propagate through space they can ________ that energy to objects in their path

Answer 21

energy

transfer

Question 22

the ________ of energy in an EM wave is describe by a vector called the ________. Its direction is the direction of ________

Answer 22

rate of flow
poynting vector
propagation

Question 23

the magnitude of the poynting vector represents the rate at which ________ flows through a unit surface area ________ to the ________ of the wave propagation, also called the ________

Answer 23

energy
perpendicular
direction
power per unit area

Question 24

the instantaneous energy density associated with the magnetic field (ub) ________ the instantaneous energy density associated with the electric field (ue)

Answer 24

equals

Question 25

the intensity of an electromagnetic wave ________ the average energy density multiplied by the speed of light

Answer 25

equals

Question 26

wave intensity I = ________ average of S over one or more cycles

Answer 26

time

Question 27

EM waves transport ________ as well as energy

Answer 27

momentum

Question 28

________ is exerted on a surface when an EM wave impinges on it

Answer 28

pressure

Question 29

if a surface absorbs all of the incident energy of an EM wave, the total ________ delivered to the surface is absorbed

Answer 29

momentum

Question 30

``` P = ________ Power = ________ ```

Answer 30

pressure | power

Question 31

if a surface is a ________, the momentum delivered in a time interval for normal incidence is now ________

Answer 31

perfect reflector | double

Question 32

a momentum (Ter/c) is delivered first by the incident wave and then again by the ________

Answer 32

reflected wave

Question 33

if the momentum doubles in a perfect reflector, then the ________ exerted on a perfect reflecting surface for normal incidence of the wave will also double

Answer 33

radiation pressure

Question 34

the apparatus for measuring radiation pressure must be placed in a high ________ to eliminate the effects of air currents

Answer 34

vacuum

Question 35

motion of a spacecraft depends on the ________ from light from the force exerted on the sail by the ________ of light from the sun

Answer 35

pressure | reflection

Question 36

EM waves travel through vacuum with ________, frequency f and ________

Answer 36

speed c | wavelength lambda

Question 37

all forms of the various types of radiation are produced by the same phenomenon: ________

Answer 37

accelerating charges

Question 38

types of light are distinguished by ________ or ________

Answer 38

frequency of wavelength

Question 39

microwaves (short-wavelength radio waves): wavelengths: ________ to ________

Answer 39

1 mm | 30 cm

Question 40

infrared waves: wavelengths: ________ to ________

Answer 40

1 mm | 7e-7 m

Question 41

infrared waves are produced by objects at ________ and by molecules, and are ________ by most materials

Answer 41

room temperature | absorbed

Question 42

visible light is produced by ________ objects like light bulb filaments and by the ________ of electrons in atoms and molecules

Answer 42

hot | rearrangement

Question 43

range of visible light is ________ (red) to ________ (violet)

Answer 43

7e-7 m | 4e-7

Question 44

ultraviolet light: wavelengths: ________ to ________

Answer 44

4e-7 m | 6e-10 m

Question 45

the sun is an important source of ________

Answer 45

UV

Question 46

x-rays: wavelengths: ________ to ________

Answer 46

10e-8 m | 10e-12 m

Question 47

most common source of x-rays is acceleration of high-energy ________ striking a metal target

Answer 47

electrons

Question 48

gamma rays: wavelengths: ________ to ________

Answer 48

10e-10 m | 10e-14 m

Question 49

gamma rays are emitted by ________

Answer 49

radioactive nuclei

Question 50

the electric and magnetic vectors associated with an electromagnetic wave are ________ to each other and to the ________ of wave propagation

Answer 50

perpendicular | direction

Question 51

polarization is a property that specifies the ________ of the electric and magnetic fields associated with an EM wave

Answer 51

directions

Question 52

the ________ of polarization is defined to be the direction in which the ________ is vibrating

Answer 52

direction | electric field

Question 53

a wave is said to be ________ if the resultant electric field vibrates in the same direction at ________ at a particular point

Answer 53

linearly polarized | all times

Question 54

the plane formed by the electric field and the direction of propagation is called the ________ of the wave

Answer 54

plane of polarization

Question 55

obtain a linearly polarized beam from an unpolarized beam by ________ all waves from the beam except those whose electric field vectors oscillate in a ________

Answer 55

removing | single plane

Question 56

the most common processes for accomplishing polarization of the beam is called ________ (uses a material that transmits waves whose electric field vectors in the plane ________ to a certain direction)

Answer 56

selective absorption | parallel

Question 57

the intensity of the transmitted beam is a maximum when the transmission axes are ________

Answer 57

parallel | 0 or 180 degrees

Question 58

the intensity is zero when the transmission axes are ________ to each other (this would cause ________)

Answer 58

perpendicular | complete absorption