1. In which method, percentage increase is assumed to be constant decade to decade?
[A] Arithmetic Progress method
[B] Incremental Increase Method
[C] Geometric Progression Method
[D] None
Answer: Option C
2. Which instrument is used to measure color in water?
[A] Tintometer
[B] Nephelometer
[C] Jackson meter
[D] Bayli’s meter
Answer: Option A
3. Which of the following is correct method of water treatment?
[A] Screening – Aeration – Sedimentation – Coagulation
[B] Coagulation – Sedimentation – Aeration – Screening
[C] Screening – Sedimentation – Aeration – Coagulation
[D] Sedimentation – Coagulation – Aeration – Screening
Answer: Option A
Explanation: The correct sequence is:
- Screening
- Aeration
- Sedimentation
- Coagulation
- Flocculation
- Filtration
- Disinfection
4. What is maximum permissible limit of fluoride in water?
[A] 1 mg/l
[B] 2.5 mg/l
[C] 3 mg/l
[D] 1.5 mg/l
Answer: Option D
5. What is the acceptable limit of hardness?
[A] 1000 mg/L
[B] 500 mg/L
[C] 300 mg/L
[D] 200 mg/L
Answer: Option D