On standard silica scale, the turbidity in drinking water should be limited to A. 10 ppm B. 20 ppm C. 30 ppm D. 50 ppm

The correct answer is A. 10 ppm.

Turbidity is a measure of the cloudiness of water. It is caused by the presence of suspended particles in the water, such as dirt, clay, and algae. Turbidity can make water difficult to see through and can also affect the taste and odor of water.

The World Health Organization (WHO) recommends that the turbidity of drinking water should not exceed 10 nephelometric turbidity units (NTU). This is equivalent to 10 parts per million (ppm) of silica.

Turbidity can be reduced by filtering the water or by using aeration to remove the suspended particles.

Here is a brief explanation of each option:

• Option A: 10 ppm. This is the recommended maximum turbidity for drinking water by the WHO.
• Option B: 20 ppm. This is twice the recommended maximum turbidity for drinking water by the WHO.
• Option C: 30 ppm. This is three times the recommended maximum turbidity for drinking water by the WHO.
• Option D: 50 ppm. This is five times the recommended maximum turbidity for drinking water by the WHO.