Water Demand, Quality and Pollution
JKSSB Junior Engineer (Civil) · Water Supply and Waste Water Engineering · 15 practice questions with answers and explanations: 7 Easy, 8 Medium, 0 Hard.
Sample questions
Sample Easy question 1
The turbidity of water is measured with a nephelometer in units of:
- pH
- NTU
- mg/L
- ppm of chlorine
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Answer: B. A nephelometer measures the light scattered by suspended particles.
Sample Easy question 2
The pH of drinking water should preferably lie between:
- 4.0 and 6.0
- 2.0 and 4.0
- 9.0 and 11.0
- 6.5 and 8.5
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Answer: D. This is the acceptable range in the drinking water standard.
Sample Easy question 3
The hardness of water is mainly caused by dissolved salts of:
- Chlorine and fluorine
- Iron and copper
- Calcium and magnesium
- Sodium and potassium
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Answer: C. It is expressed in mg/L as CaCO₃.
Sample Medium question 4
Water with 80 mg/L of calcium has a hardness of about:
- 80 mg/L as CaCO₃
- 400 mg/L as CaCO₃
- 200 mg/L as CaCO₃
- 32 mg/L as CaCO₃
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Answer: C. Calcium is converted to CaCO₃ by multiplying by 100 ÷ 40 = 2.5.
Sample Medium question 5
The average daily demand of a town is 5 MLD. If the maximum daily demand is 1.8 times the average, it is:
- 4 MLD
- 9 MLD
- 7.5 MLD
- 13.5 MLD
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Answer: B. 5 × 1.8 = 9 MLD.
Sample Medium question 6
Fluoride in drinking water above 1.5 mg/L can cause:
- Goitre
- Cholera
- Fluorosis
- Typhoid
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Answer: C. Fluorosis affects the teeth and bones.