$A$ lake with an inflow of domestic sewage rich in organic waste may result in:

Given below are two statements:
Statement $I$: Electrostatic precipitator is most widely used in thermal power plants.
Statement $II$: Electrostatic precipitator in thermal power plants removes ionising radiations.
In the light of the above statements,choose the most appropriate answer from the options given below:

Which is not an effect of acidic rain in a pond?

The cause of water bloom is ..........

Define/Explain: Noise.

If the concentration of $DDT$ in water is $0.003\, ppm$,what could be its concentration in small fish due to biomagnification (in $, ppm$)?