Physics 24.0-24.1

sound waves are electromagnetic waves(T/F)

F

radio waves are electromagnetic waves(T/F)

T

changing magnetic field induces an emf and therefore an electromagnetic field(T/F)

T

electric field lines start positive and end negative(T/F)

T

magnetic fields are generated by moving charges or changing electric fields(T/F)

T

magnetic field lines are continuous with no beginning or end(T/F)

T

electromagnetic waves

radio, visible light, infared, UV, Xray, gamma ray

sound waves

sound creates pressure waves in matter, like water, not electromagnetic

radio waves

do not need a medium to travel, can travel through a vacuum like space, electromagnetic

electromagnetic waves require a material medium to travel

F

all electromagnetic waves travel at the same speed in a vacuum

T

visible light is an electromagnetic wave

T

electromagnetic waves can travel through empty space

T

electromagnetic waves consist of oscillating electric and magnetic fields

T

speed of electromagnetic waves in a vacuum depends on frequency

F

increasing frequency of electromagnetic waves increases wavelength

F

microwaves are used in communication and cooking because they are electromagnetic waves

T

gamma rays have the highest energy on the electromagnetic spectrum

T

electric and magnetic field in an electromagnetic wave are parallel to each other

F

magnetic fields are generated by moving charges or by changing electric fields

T

a changing magnetic field induces an electromotive force(emf) and hence an electric field

T

magnetic field lines are continuous, having no beginning or end

T

magnetic monopoles are known to exist

F

electric field lines/ gauss law of electromagnetism

originate on a positive charge and terminante on a negative charge

magnetic field lines, gauss law of magnetism

continuous, no beginning or end, no magnetic monopols

faradays law of induction/ lenz law

a changing magnetic field induces an electromagnetic force(emf) and an electric field, the direction of the emd opposes the change

amperes law

Magnetic fields are generated by moving charges or by changing electric fields

oscilating charges produce changing electric field

T

electromagnetic waves are capable of exterting forces great distances from their source

T

SI unit for frequency

1 Hz, 1 cycle/sec

electromagnetic waves propogate at the speed of light (3×10^8)

T

a changing electric field can produce a magnetic field

T

maxwell added the displacement current term to amperes law to account for changing electric fields

T

electromagnetic waves were predicted by maxwells equations before they were experimentally observed

T

the speed of electromagnetic waves depends on the strength of the electric field

F

In an electromagnetic wave, the electric and magnetic fields oscilate perpendicular to each other

T

maxwells eqautions predict that electromagnetic waves travel at the speed of light in a vacuum

T

a cosntant unchanging magnetic field can induce an electric field

F

electromagnetic waves carry energy through space

T

the direction of wave propogation is parallel to both the electric and magnetic fields

F

changing magnetic fields are described by faradays law of induction

T

the displacement current is only present when actual charges are moving in a conductor

F