Noise & Radiation
Environment · ध्वनि और विकिरण
📋Quick Overview
Key facts about Noise & Radiation for RRB NTPC, SSC CGL, and other competitive exams. These are frequently asked in the GK section and mastering them ensures easy marks.
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Safe noise level — < 85 dB — Prolonged exposure above 85 dB causes hearing damage
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Whisper — 20-30 dB — Very quiet
📖Noise & Radiation
| Name | Detail | Key Fact |
|---|---|---|
| Safe noise level | < 85 dB | Prolonged exposure above 85 dB causes hearing damage |
| Whisper | 20-30 dB | Very quiet |
| Normal conversation | 60-70 dB | Comfortable level |
| Jet engine | 140+ dB | Pain threshold, immediate damage |
| UV radiation | From Sun | Causes skin cancer, cataracts — blocked by ozone |
| Radioactive waste | From nuclear plants | Needs thousands of years to become safe |
| Chernobyl | 1986 | World's worst nuclear disaster — Ukraine (then USSR) |
📝Key Points
- •Safe noise level: < 85 dB: Prolonged exposure above 85 dB causes hearing damage
- •Whisper: 20-30 dB: Very quiet
- •Normal conversation: 60-70 dB: Comfortable level
- •Jet engine: 140+ dB: Pain threshold, immediate damage
- •UV radiation: From Sun: Causes skin cancer, cataracts — blocked by ozone
- •Radioactive waste: From nuclear plants: Needs thousands of years to become safe