The electric field of an electromagnetic wave propagating through free space is
ID: 2077927 • Letter: T
Question
The electric field of an electromagnetic wave propagating through free space is given by E = 100 cos (3 times 10^8t +) V/m (t in; x, y in). the magnetic field intensity vector of the wave is (free space impedance is 377 Ohm). (a) H = 0.265 cos (3 times 10 t - x) z A/m (b) H = 37/7 cos (3 times 10^8 t - y) times A/m (c) H = 37.7 cos (3 times 10^8 t - x) y A/m (d) H = 0.265 cos (3 times 10^8 t + x) y A/m (e) H = 0.265 cos (3 times 10 t + y) (-x) A/m (f) H = 0.265 cos (3 times 10^8 t + x) (-y) A/m The complex rms magnetic field intensity vector of an electromagnetic wave traveling through air can be expressed as H = 0.1e times A/m (y in m). The angular (radians) frequency omega of the wave amounts to (a) 0.477 times 10^9 rad/s. (b) 3 times 10^7 rad/s. (c) 0.477 times 10^7 rad/s (d) 3 times 10^8 rad/s. (e) 3 times 10^9 rad/s. (f) Need more information. Due to the salt content, sea (salty) water in much more electrically conductive than fresh water. If a radio transmitter and a radio receiver are submerged in a lake, the communication is better for (a) a freshwater lake. (b) a salty lake. (c) No difference. With and k the appropriate which of the following expressions represents the complex electric field vector of a uniform plane harmonic electromagnetic wave propagating in free space along the diagonal of the first octant of the Cartesian coordinate system, so that its direction of propagation equals angles with all three coordinate axes? (a) E = E_0 (x + y + z) e (b) E = E_0 (x + y + z) e (c) E = E_0 (x + y + z) e (d) E = E_0 (x - 2y + z) e (e) None of the above.Explanation / Answer
11) Due to the salt content sea (salty) water is much more electrically conductive than fresh water if a radio transmitter and a radio reciver are submerged in a lake the communication is better for
(c) A salty lake