1. Which one of the following gases is the principal by-product of anaerobic decomposition of the organic content in wastewater?
[A] Ammonia
[B] Methane
[C] Hydrogen sulphide
[D] Carbon monoxide
Answer: Option B
2. Aerosol is _____.
[A] Finely divided particles of ash
[B] Carbon particles of microscopic size
[C] Diffused liquid particles
[D] Dispersion of small solid or liquid particles in gaseous media
Answer: Option D
3. What type of noise be abated by providing lining on walls and ceiling with sound absorbing material?
[A] Structural noise
[B] Source noise
[C] Direct air-borne noise
[D] Reflection noise
Answer: Option D
4. In sanitary plumbing of buildings, a two-pipe system signifies ______.
[A] A soil-cum-waste pipe and as ventilating pipe
[B] Separate soil pipe and waste pipe, each with its own vent pipe
[C] Separate soil waste pipe and a common ventilating pipe
[D] Separate soil pipes and waste pipes without vent pipes
Answer: Option B
5. Sludge Bulking can be controlled by ______.
[A] Denitrification
[B] Aeration
[C] Coagulation
[D] Chlorination
Answer: Option D