Electromagnetic radiation is more common than you might expect. Radio and TV stations emit radio waves as they broadcast their programs; microwaves cook your food in a microwave oven; conventional ovens and stoves emit infrared and slightly visible radiation; dentists use X rays to check your teeth; and cell phones operate using microwaves as well, but at a lower frequency than microwave ovens. Even though they have different names and different applications, these types of radiation are really all the same thing: electromagnetic (EM) waves - energy that travels in the form of oscillating electric and magnetic fields.
None of these technologies use radio waves.
None of these technologies use lower-frequency microwaves.
None of these technologies use higher-frequency microwaves.
None of these technologies use infrared waves.
The radiation emitted by some wireless local area networks has the shortest wavelength of all the technologies listed above.
All these technologies emit waves with a wavelength in the range 0.01 to 10.0 km.
All these technologies emit waves with a wavelength in the range 0.01 to 10.0 m.
Despite their extensive applications in communication systems, radio waves and microwaves are not the only form of EM waves present that play a significant role in our life (and the life of our planet): sunlight.
The sun emits over a wide range of frequencies; however, the fraction of its radiation that reaches the earth's surface is mostly in the visible range. (Much of the radiation at other frequencies is absorbed directly by the atmosphere before even reaching the earth's surface.) The earth, then, absorbs this radiation and reemits it as
Based on this information, which of the following statements is correct?
Check all that apply.
The earth absorbs visible light and emits radiation with a shorter wavelength.
The earth absorbs visible light and emits radiation with a longer wavelength.
The earth absorbs visible light and emits radiation with a lower frequency.
The earth absorbs visible light and emits radiation with a higher frequency.
