The unit of decibels (dB) is used to measure the ________ pollution.
Answer & explanation
Correct answer: option 4
The correct answer is Option (4) → Noise
The decibel (dB) is the unit of sound level, so it measures noise pollution.
NCERT (2026-27): “Noise Pollution … The main sources of noise pollution are various factories, mechanised construction and demolition works, automobiles and aircraft, etc. There may be added periodical but polluting noise from sirens, loudspeakers used in various festivals, programmes associated with community activities. The level of steady noise is measured by sound level expressed in terms of decibels (dB).” |