Water Quality Parameters MCQ with answer and solution

Concept

Turbidity measures how suspended particles scatter or block light passing through water. It is an optical (light) property.

Step-by-step solution

1. Look for the parameter linked with light. 2. Turbidity is measured by light scattering (nephelometer, NTU) or light absorption (Jackson candle turbidimeter, JTU). 3. pH, alkalinity and volatility are chemical properties, not light properties. 4. Answer is (A) Turbidity.

Explanation

Turbidity is caused by suspended particles that scatter and absorb light. So it measures the light-related (optical) property of water or wastewater. The other options are chemical properties.

Why the other options are wrong

B: pH measures hydrogen ion concentration. C: Alkalinity measures the capacity to neutralise acid. D: Volatility relates to substances that evaporate easily, not to light.

Shortcut

Any 'light' word in the question → turbidity (NTU).

Common mistake

Getting confused by the word 'emitting'. Water does not emit light; turbidity relates to light passing through or being scattered.