JEE Main 2022 · 29 July · morning · Single correct · +4 / −1
Match List - I with List - II :
Choose the correct answer from the options given below :
| List - I | List - II | ||
|---|---|---|---|
| (a) | UV rays | (i) | Diagnostic tool in medicine |
| (b) | X-rays | (ii) | Water purification |
| (c) | Microwave | (iii) | Communication, Radar |
| (d) | Infrared wave | (iv) | Improving visibility in foggy days |
- (a) (a)-(iii), (b)-(ii), (c)-(i), (d)-(iv)
- (b) (a)-(ii), (b)-(i), (c)-(iii), (d)-(iv)
- (c) (a)-(ii), (b)-(iv), (c)-(iii), (d)-(i)
- (d) (a)-(iii), (b)-(i), (c)-(ii), (d)-(iv)
Answer and solution
Answer (b) (a)-(ii), (b)-(i), (c)-(iii), (d)-(iv)
Solution
Physics sir · 2 steps
Tie each band to what its wavelength lets it do, and the four uses fall into place.
- Think about wavelength. Each use depends on one property of the wave: how much energy it carries, how easily it passes through matter, or how little it scatters.
Radiation Property that matters Use UV rays High-energy photons kill bacteria (ii) water purification X-rays Pass through soft tissue, stopped by bone (i) diagnostic tool in medicine Microwave Short enough to send as a narrow beam, long enough to pass through the atmosphere (iii) communication, radar Infrared wave Longer than visible light, so fog scatters it less (iv) improving visibility in foggy days - So. The match is (a)-(ii), (b)-(i), (c)-(iii), (d)-(iv), which is option (b).
The idea to keep. For spectrum matching, ask what each wavelength does well: UV kills germs, X-rays see through tissue, microwaves carry signals and radar, and infrared gets through fog and haze.
Answer from the NTA final answer key. Solution by PrepWiser.