1. The bacterias which require free oxygen for their survival, are called ______.
[A] Anaerobic bacteria
[B] Facultative bacteria
[C] Aerobic bacteria
[D] None
Answer: Option C
2. Mostly used coagulant, is ______.
[A] Lime
[B] Chlorine
[C] Alum
[D] Bleaching powder
Answer: Option C
3. Gravity conduits are generally in the form of _____.
[A] Flumes
[B] Aqueduct
[C] Canals
[D] All the above
Answer: Option D
4. Normal values of overflow rate for plain sedimentation tank, is _____ litres/hr/m^2.
1000 to 1250
750 to 1000
500 to 750
250 to 500
Answer: Option C
5. The bed slope in slow sand filters, is generally kept ______.
[A] 1 in 75
[B] 1 in 200
[C] 1 in 100
[D] 1 in 50
Answer: Option C