Physics
What are infrared radiations? How are they detected? State one use of these radiations.
Answer
The electromagnetic waves of wavelength λ = 8000 Å to 107 Å are called infrared radiations.
For the detection of infrared radiations —
If a thermometer having it's bulb blackened is moved from the violet end towards the red end of the spectrum of visible light, it is observed that there is a very slow rise in temperature. But when this thermometer is moved beyond the red extreme, a rapid rise in temperature is noticed.
It means that the part of spectrum beyond the red extreme of the visible light has certain radiations which produce a strong heating effect, but they are not visible. These radiations are called the infrared radiations.
The infrared radiations are used for therapeutic purposes by doctors.
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