RAS question
Terahertz (THz) technology, expected to be key for 6G, operates between:
Correct answer: (A) Microwaves and infrared.
Terahertz technology operates in the electromagnetic spectrum between microwaves and infrared radiation.
Explanation
Terahertz waves occupy the band between microwaves and infrared radiation, so option A matches their position in the electromagnetic spectrum. National Institute of Standards and Technology describes terahertz radiation as lying between these two regions and gives its frequency range as about 30,000 crore to 3 lakh crore cycles per second. THz waves are broadly placed at 0.1-10 THz, with wavelengths from 3 mm to 30 micrometres. This placement matters for 6G because THz bands are expected to enable terabits-per-second data rates, but their very short range means networks would need dense architecture rather than relying on long-distance coverage.
Why the other options are wrong
- (B) Radio waves and microwaves lie below the terahertz region, while terahertz radiation lies above microwaves and below infrared.
- (C) Infrared and visible light are above the terahertz region; terahertz radiation is on the microwave side of infrared, not beyond it.
- (D) Visible and ultraviolet radiation are still higher-frequency parts of the spectrum, far above the microwave-to-infrared position of terahertz waves.
Concept
This tests the Science and Technology part of the RAS syllabus that links the electromagnetic spectrum with emerging communication technologies. It recurs because 6G, spectrum use and applied physics are current, exam-friendly ways to test basic frequency-band understanding.