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Railways PYQCBT 2 2017

RRB NTPC · Question 14

To determine the health of a water body, what is measured?

  1. Dissolved Oxygen

  2. Dissolved Fluorine

  3. Dissolved Methane

  4. Dissolved Calcium

Show answer & explanation

Answer: (A) Dissolved Oxygen

Explanation

Dissolved oxygen is the key indicator of a water body's health: aquatic life needs it, and organic pollution lowers it by raising the biological oxygen demand.