Water Quality – MCQ

1. Temporary hardness in water is caused by

a) Bi-nitrates of Ca ⁺⁺ and Mg ⁺⁺
b) Sulphate of Ca⁺⁺ and Mg ⁺⁺
c) Carbonates of Ca⁺⁺ and Mg⁺⁺
d) Nitrates of Ca⁺⁺ and Mg⁺⁺

2. As per Indian standard, the safe permissible limit of Arsenic in potable water is

a) 0.02 mg/l
b) 0.5 mg/l
c) 0.10 mg/l
d) 0.05 mg/l

3. Maximum permissible turbidity for drinking water based on silica scale is

a) 50 ppm
b) 10 ppm
c) 5 ppm
d) 20 ppm

4. Which of the following can be used for water disinfection?

a) Ozone
b) Chlorine
c) Hydrogen peroxide
d) None of these

5. Which of the following methods are used for water purification?

a) Screening
b) Fluoridation
c) Disinfection
d) All of the above
e) Only (a) and (c)

6. Screening is the process which helps to remove

a) Large particles
b) Very Small particles
c) Colloidal particle
d) None

7. Which of the following factors affect the process of sedimentation

a) Velocity of flow
b) Viscosity of water
c) Specific gravity of the particles
d) All of these

8. The value of uniformity co-efficient for rapid gravity filters is

a) 3 to 3.5
b) 1.8 to 2.5
c) 1.3 to 1.7
d) 0.3 to 1.2

9. The value of uniformity co-efficient for slow gravity filters is

a) 3 to 3.8
b) 1.8 to 2.5
c) 1.3 to 1.7
d) 1 to 1.2

10. The uniformity co-efficient is express as

a) D₆₀/D₁₀
b) D₁₀/D₆₀
c) D₁₀/D₅₀
d) None

11. The filters works under pressure is known as

Read More:

Sources of Water – MCQ

Water Demand

• Water Supply - MCQ