Question

The earth’s atmospheric window is in the:
a. Ultraviolet region
b. Visible region
c. Infrared region
d. Polar region

Answer 1

One important physical effect of electromagnetic radiation 's contact with matter and of our environment 's precise structure is that only light will enter the atmosphere well in some wavelength areas. Such regions are called windows of the atmosphere.

Complete answer:
• Ultraviolet radiation refers to the area between visible light and X-rays on the electromagnetic spectrum, with a wavelength falling from 400 to 10 nanometers.
• The visible spectrum is the part that is visible to the human eye in the electromagnetic spectrum. Electromagnetic radiation is called visible light or simply light in this range of wavelengths. For wavelengths from around 380 to 740 nanometers, a normal human eye can respond.
• The polar regions of the World are those areas found between the North or South Pole and the Arctic or Antarctic Rings. The Arctic, called the northern polar region, covers the Arctic Ocean and a portion of some of the surrounding land masses.
• Between the visible and microwave portions of the electromagnetic spectrum lies infrared light. Infrared light has a wavelength spectrum, just like visible light has wavelengths that differ from red to violet light. "Near infrared" light is nearest to visible light in wavelength and "far infrared" is similar to the electromagnetic spectrum's microwave field. The longer, far infrared wavelengths are about the size of a pin head and the cell size is the shorter, near infrared ones.
• We know that infrared light is emitted by many things. But many things, especially near infrared light, reflect infrared light as well. Near infrared radiation-unless the object is very hot-is not related to the temperature of the object being photographed.
• Infrared film 'sees' the object when it is mirrored or absorbed by the object when the Sun (or some other light source) reflects infrared light on it. We might assume that this reflection or absorption of infrared helps to decide the object's 'colour'-the colour is a mixture of red , green , blue, and infrared.

Hence, the correct answer is option (C).

Note: In the visible and radio frequency regions, the dominant windows in the atmosphere are seen to be, while X-Rays and UV are seen to be very strongly absorbed and Gamma Rays and IR are somewhat less strongly absorbed. In order to observe at wavelengths other than visible and RF zones, we see distinctly the case for getting above the atmosphere with detectors on space-borne platforms.