ANS:B - 0.5 to 50

The electromagnetic spectrum range, which is important for radiation, varies from 0.5 to 50 microns. Explanation:

• The electromagnetic spectrum encompasses a wide range of wavelengths, from very short gamma rays to very long radio waves.
• In the context of radiation, particularly thermal radiation emitted by objects due to their temperature, the range of wavelengths that are most relevant lies in the infrared region of the spectrum.
• The infrared region spans from approximately 0.7 microns (near-infrared) to about 1000 microns (far-infrared).
• However, the range of 0.5 to 50 microns is particularly important for radiation in many practical applications, including thermal imaging, remote sensing, and infrared spectroscopy.
• Within this range, the shorter wavelengths (0.5 to 5 microns) correspond to the near-infrared region, while the longer wavelengths (5 to 50 microns) correspond to the mid-infrared region.
• Objects at ordinary temperatures emit radiation primarily in the mid-infrared range, making this range particularly relevant for thermal imaging and heat transfer applications.