Assertion A: Slow sand filters are more efficient in removal of bacteria than rapid sand filters. Reason R : The sand used in slow sand filters is finer than that in rapid sand filters. Select your answer based on the coding system given below? September 7, 2025 by Admin A. Both A and R are true and R is the correct explanation of A B. Both A and R are true but R is not the correct explanation of A C. A is true but R is false D. A is false but R is true ✅ The correct answer is option A.
Standard EDTA (ethylene diamine tetra acetic aciD. solution is used to determine the_______________? September 7, 2025 by Admin A. hardness in water B. turbidity in water C. dissolved oxygen in water D. residual chlorine in water ✅ The correct answer is option A.
Air binding phenomena in rapid sand filters occur due to_________________? September 7, 2025 by Admin A. excessive negative head B. mud ball formation C. higher turbidity in the effluent D. low temperature ✅ The correct answer is option A.
As compared to higher pH values, the contact period required for efficient chlorination at lower pH values is___________________? September 7, 2025 by Admin A. smaller B. larger C. same D. none of the above ✅ The correct answer is option A.
Double filtration is used_______________? September 7, 2025 by Admin A. to increase the filtration slow sand filters capacity of B. to increase the filtration rapid sand filters capacity of C. for isolated buildings like pools, hotels etc swimming D. all of the above ✅ The correct answer is option A.
The suitable method for disinfection of swimming pool water is________________? September 7, 2025 by Admin A. ultra violet rays treatment B. lime treatment C. by using potassium permanganate D. chlorination ✅ The correct answer is option A.
Assertion A : The consumption of water increases with increase in the distribution pressure. Reason R : Higher distribution pressure causes more loss and waste of water. Select your answer according to the coding system given below? September 7, 2025 by Admin A. Both A and R are true and R is the correct explanation of A B. Both A and R are true but R is not the correct explanation of A C. A is true but R is false D. A is false but R is true ✅ The correct answer is option A.
The hourly variation factor is usually taken as______________? September 7, 2025 by Admin A. 1.5 B. 1.8 C. 2.0 D. 2.7 ✅ The correct answer is option A.
On standard silica scale, the turbidity in drinking water should be limited to_______________? September 7, 2025 by Admin A. 10 ppm B. 20 ppm C. 30 ppm D. 50 ppm ✅ The correct answer is option A.
In chlorination, with the rise in temperature of water, death rate of bacteria____________? September 7, 2025 by Admin A. increases B. decreases C. remains unaffected D. none of the above ✅ The correct answer is option A.