Question

Noise pollution is measured in
a. Hertz
b. Fathoms
c. Nanometres
d. Decibels

Answer 1

Hint: Introduction of contamination into our natural environment that damages or changes our environment is known as pollution and the substances that cause pollution are called pollutants. Pollution forms are chemical substances or energy like noise, heat or light.

Complete answer:
Hertz is the unit of frequency in the SI and it is defined also as one cycle per second. Heinrich Rudolf Hertz was the first person who proved the existence of electromagnetic waves, after that this unit was named as Hertz. So Hertz is not the correct answer to this question.
Fathom is the unit of length, and this unit is used to measure the depth of water.

> 1 fathom is equal to $1.8 metres$
Nanometre is the unit of length; one nanometre is equal to one millionth of a millimetre. When the things are too small and can’t be seen by naked eye, these objects are measured by nanometres. These objects are only seen by electron microscopes only.

> One nanometre = $10^{-9} metres$
A decibel is the unit of sound that means the quality of sound is measured in decibels, and it’s denoted as dB.

> 1 decibel is equal to 10 times the common logarithm of the power ration.
Noise pollution is caused by the increased level of sound and it is measured by decibels units.

Hence, the correct answer is option (D).

Note: As per the recent study, Guangzhou the city of china is the highly noise polluted city in the world, and it’s not a surprise to know that New Delhi the city of India is the second noisiest country in the world.