dB is a standard abbreviation used for the quantitative expression of
the density of bacteria in a medium
a particular pollutant
the dominant Bacillus in a culture
a certain pesticide
As discussed in
Noise -
Noise is undesired high level of sound. We have got used to associating loud sounds with pleasure and entertainment not realising that noise causes psychological and physiological disorders in humans.
- wherein
A brief exposure to extremely high sound level, 150 dB or more generated by take off of a jet plane or rocket, may damage ear drums thus permanently impairing hearing ability.
dB is abbreviated for decimal. It's a unit of sound and hence used to measure sound pollution.
Option 1)
the density of bacteria in a medium
This solution is incorrect
Option 2)
a particular pollutant
This solution is correct
Option 3)
the dominant Bacillus in a culture
This solution is incorrect
Option 4)
a certain pesticide
This solution is incorrect