Test: Quality Control of Water Supply - 1 - Civil Engineering (CE) MCQ

Let's analyze each statement to determine which one(s) are correct:

1. **Turbidimeters are frequently used to measure turbidities of raw supplies**:
   - This statement is generally true. Turbidimeters are instruments used to measure the turbidity (cloudiness or haziness) of water, which can be done for raw water supplies to assess water quality.

2. **Turbidimeters are frequently installed online in treatment plants to measure turbidities of sedimented filtered waters**:
   - This statement is also true. Turbidimeters are often installed in-line in water treatment plants to continuously monitor the turbidity levels of treated water after filtration.

3. **Nephelometers are frequently used to check and measure the turbidities of final disinfected supplies**:
   - This statement is incorrect. While nephelometers are used to measure suspended particles or colloids in a liquid by detecting light scattered at right angles (nephelometry), they are not specifically used to measure the turbidity of disinfected water supplies. Turbidimeters are more commonly used for measuring turbidity in water.

Given the analysis:

- Statement 1 is correct.
- Statement 2 is correct.
- Statement 3 is incorrect.

Therefore, the correct answer is:

**4. All of the above**

The correct option is D 1 mg/L platinum in form of chloroplatinate ion
TCU is the colour unit and represented by colour produced by 1 mg/L of platinum in the form of chloroplatinate ion dissolved in 1 L of distilled water.

Threshold odour number represents the dilution ratio at which the odour is hardly detectable,
TON  = 200/40 = 5

Water with hardness upto 75 ppm are considered soft while those with 200 ppm and above are considered hard. In between the waters are considered as moderately hard.

High quantities of copper are likely to affect human lungs and other respiratory organs.

Higher concentration of iron above 0.3 ppm causes discolouration of clothes and incrustation in water mains.

Eriochrome black T is used to measure hardness. Phenolphthalein is used to measure alkalinity. Blue litmus is used to measure acidity of water.