Select True or False for the following statements about electromagnetic waves. Gamma rays travel in vacuum at the same speed as the visible light. Radio waves have wavelengths longer than 1 m. The sun's radiation is most intense in the infrared region. Radio waves travel in vacuum at a lower speed than the visible light. The Earth's atmosphere is quite transparent to infrared radiation. X-rays travel in vacuum at a higher speed than the visible light. A vertical automobile antenna is sensitive to electric fields polarized vertically. Tries 0/20

a) Gamma rays travel in vacuum at the same speed as the visible light True

b) Radio waves have wavelengths longer than 1 m True

c) The sun's radiation is most intense in the infrared region False

d) Radio waves travel in vacuum at a lower speed than the visible light False

e) The Earth's atmosphere is quite transparent to infrared radiation True

f) X-rays travel in vacuum at a higher speed than the visible light False

g) A vertical automobile antenna is sensitive to electric fields polarized vertically True

Explanation:

a) All electromagnetic waves travel at the same speed of 3 x 10^8 m/s in a vacuum

b) radio wave can have frequency ranging from 300 GHz with wavelength of 1 mm to frequency of 30 Hz with wavelength of 10000 km

c) Most of the radiation of the sun is spread out as visible rays, so the sun's radiation is intense in the visible ray region.

d) Explanation is the same as that of a. above

e) This is easy to see in the fact that the heat from the sun can reach us here on the Earth's surface. If it were not true, we won't receive the sun's heat through our atmosphere

f) Same explanation as a. above

g) Antenna are more sensitive to radio waves with their electric fields polarized in the same orientation as their components. This means that vertical antenna will only work best in receiving a vertically polarized radio wave, and a horizontally oriented antenna will work best with a radio wave polarized with its electric field to the horizontal. In theory, an antenna receiving a signal polarized at perpendicularly to its component will not work.