Which of the following instruments is used for determining the turbidity of the water?

Explanation

Turbidity is a measure of how cloudy or murky water is due to the presence of suspended particles. To determine the turbidity of water, an instrument is needed. In this Biology question, we are asked to identify which instrument is used to determine the turbidity of water. Option A, thermometer, is not the correct answer. A thermometer is used to measure temperature, not turbidity. Option C, rain gauge, is also incorrect. A rain gauge is used to measure the amount of rainfall, not the turbidity of water. Option D, hygrometer, is also not the correct answer. A hygrometer is used to measure humidity, not the turbidity of water. The correct answer to this question is option B, Secchi Disc. A Secchi Disc is a circular disk typically painted white and black or white and red, which is lowered into the water until it disappears from sight. The depth at which it disappears gives a measure of the turbidity of the water. In conclusion, the instrument used for determining the turbidity of water is the Secchi Disc. Other instruments such as thermometer, rain gauge, and hygrometer are used to measure different environmental variables.