Author Question: At every instant the ratio of the magnitude of the electric to the magnetic field in an ... (Read 62 times)

kaid0807 · **on:** Jul 28, 2018

At every instant the ratio of the magnitude of the electric to the magnetic field in an electromagnetic wave in vacuum is equal to
a. the speed of radio waves.
b. the speed of light.
c. the speed of gamma rays.
d. all of the above. e. only (a) and (b) above.

Question 2

Magnetic fields are produced by
a. constant electric currents.
b. electric currents that vary sinusoidally with time. c. time-varying electric fields.
d. all of the above. e. only (a) and (b) above.