Excessive nutrients in a fresh-water body cause fish mortality. Give two reasons.

Name three common fresh-water food fishes.

The green scum seen in the fresh water bodies is:

Cigarette smoking causes emphysema. Give reason.

Give three examples of fresh water ecosystem.

What is the need for modulation of a signal ? Give two reasons.

Give the term for the study of fresh water bodies.

A concave miror is placed in water will there be any change in focal length? Give reason?

Out of BaCl_2 and KCl which one is more effective in causing coagulation of negatively charged colloidal sol. Give reason.

If a freshwater fish is placed in an aquarium containing sea water, will the fish be able to survive? Explain giving reasons.