General Physics

Electromagnetic Waves

1. How long does it take light to reach us from the Sun, 1.5x10^8 Km away? O 7.33 minutes 8.33 minutes O 500 seconds O 600 seconds 2. An EM wave has frequency 7.14x10^14 Hz. What is its wavelength, and how would we classify it? 4.2x101-7m 6.2x101-7 m 5.2x101-7 m 7.2 x101-7m3. In an EM wave traveling west, the B field oscillates upand down vertically and has a frequency of 90.0 kHz andan rms strength of 7.75x10^-9 T. Determine the frequency and rms strength of the electric field. What is the direction of its oscillations? frequency = 60kHz, rms strength of O the electric field = 3.33 V/m, direction = east and west horizontally frequency = 60kHz, rms strength of O the electric field = 2.33 V/m, direction = east and west horizontally frequency = 90kHz, rms strength of O the electric field = 2.33 V/m, direction = east and north horizontally frequency = 90kHz, rms strength of O the electric field = 2.33 V/m, direction = north and south horizontally4. If the magnetic field in a traveling EM wave has a peak magnitude of 10.5 nT, what is the peak magnitude of the electric field? 6. V/m 5. V/m O 4.15 V/m 3.15 V/m 5 An EM wave has a wavelength of 720 nm. What is its frequency, and how would we classify it? O 5.2x10^14 Hz 6.2x10^14 Hz 4.2x10^14 Hz O 7.2x10^14 Hz6. If the electric field in an EM wave has a peak magnitude of 0.72x10^-4 V/m what is the peak magnitude of themagnetic field strength? O 2.4X101-11 T 2.4x101-12 T 3.4X101- 14 T 2.4X101-13 T