Question

Which of the following represents the decibel level of rustling of tree leaves in normal circumstances?
1. 10 db
2. 20 db
3. 60 db
4. 100 db

Answer 1

Correct Answer - Option 2 : 20 db

The correct answer is 20 db.

 

• A decibel is a logarithmic unit used to measure sound level.
• It is also widely used in electronics, signals, and communication.
• The higher the decibel level, the louder the noise.
• On the decibel scale, a level increase of 10 means that a sound is actually 10 times more intense, or powerful.
• A whisper is about 30 dB and a normal conversation is about 60 dB. 
• Noise above 70 dB over a prolonged period of time may start to damage our hearing and Loud noise above 120 dB can cause immediate harm to our ears.
• The decibel level of the rustling of tree leaves in normal circumstances is 20 dB.

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• The Central Pollution Control Board laid down the permissible noise level in India for different areas.
  • In industrial areas, the permissible limit is 75 dB for daytime and 70 dB at night.
  • In commercial areas, it is 65 dB and 55 dB while in residential areas it is 55 dB and 45 dB during daytime and night respectively.