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Q23
(IAS/2009)
Science & Technology › Basic Science (Physics, Chemistry, Biology) › Waves and acoustics
Answer Verified
Which one of the following types of waves are used in a night vision apparatus ?
Result
Your answer:
—
·
Correct:
C
Explanation
Night-vision devices rely on detecting infrared (IR) radiation, which lies just beyond visible red and is emitted as heat by objects at typical temperatures. Specialized sensors in night-vision goggles and thermal imagers pick up these IR wavelengths and electronically convert the detected infrared image into a visible display, enabling vision in darkness [2]. Because radio waves and microwaves occupy much longer wavelengths and are not the basis for thermal imaging or typical night-vision optics, the correct choice is infrared waves. The cited references explicitly state that night-vision equipment and goggles detect infrared radiation and convert it into a visible image for the user [2].
Sources
- [1] https://imagine.gsfc.nasa.gov/science/toolbox/emspectrum1.html
- [2] https://acd-ext.gsfc.nasa.gov/anonftp/acd/daac_ozone/Lecture4/Text/Semifinal/blackbodyintro.html
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