A. 4 mm/hr
B. lOmm/hr
C. 20 mm/hr
D. 40 mm/hr
✅ The correct answer is option D.
Environmental Engineering MCQs
The layout of distribution system in which water flows towards the outer periphery is_________________?
A. ring system
B. dead end system
C. radial system
D. grid iron system
✅ The correct answer is option C.
Sewerage system is designed for_______________?
A. maximum flow only
B. minimum flow only
C. average flow only
D. maximum and minimum flow
✅ The correct answer is option D.
The polluted water is one which_______________?
A. contains pathogenic bacteria
B. consists of undesirable substances rendering it unfit for drinking and domestic use
C. is safe and suitable for drinking and domestic use
D. is contaminated
✅ The correct answer is option B.
The main disadvantage of cement concrete sewers is________________?
A. less strength
B. difficulty in construction
C. difficulty in transportation due to heavy weight
D. less life
✅ The correct answer is option C.
In a BOD test, 1.0 ml of raw sewage was diluted to 100 ml and the dissolved oxygen concentration of diluted sample at the beginning was 6 ppm and it was 4 ppm at the end of 5 day incubation at 20°C. The BOD of raw sewage will be___________?
A. 100 ppm
B. 200 ppm
C. 300 ppm
D. 400 ppm
✅ The correct answer is option B.
The phenolic compounds in public water supply should not be more than_______________?
A. 0.1 ppm
B. 0.01 ppm
C. 0.001 ppm
D. 0.0001 ppm
✅ The correct answer is option C.
The dissolved oxygen level in natural unpolluted waters at normal temperature is found to be of the order of________________?
A. 1 mg/litre
B. 10 mg/litre
C. 100 mg/litre
D. 1000 mg/litre
✅ The correct answer is option B.
Orthotolidine test is used for determination of________________?
A. dissolved oxygen
B. residual chlorine
C. biochemical oxygen demand
D. dose of coagulant
✅ The correct answer is option B.
Settling velocity increases with_______________?
A. specific gravity of solid particles
B. size of particles
C. depth of tank
D. temperature of liquid
✅ The correct answer is option C.