761. Mostly the salt of calcium and Magnesium can not cause ________________?
762. The water in swimming pools can be ____________ by using any one from the following, chlorine-ultraviolet rays and bromine t ?
763. A digging out of earth to make trench for any engineering purpose is called ______________________?
C. borrow pitting
D. Earth filling
764. Velocity of flow in a sewer must be form ______________ to ?
A. 1 m / sec to 3m/ sec
B. 3m / sec to 4m/ sec
C. 4m / sec to 4.5 ml sec
D. 4.5 ml sec to 5 m/ sec
765. The aeration of water is done to remove _________________?
766. A module or outlet in which discharge is fixed and limited, irrespective fluctuations in water levels in distributary is called _________________?
D. Semi – Rigid
767. When the rate of change of discharge of outlet equals the rate of change of discharge of the channel, the out let is called __________________?
768. When the high flood level of the drain is sufficiently below the bed of the Canal that the drainage water flows freely under gravity, such structure is called___________________?
D. Non-gravity structure
769. When FSL of the canal is sufficiently above the bed level of drainage so that canal flows under syphonis action, the structure is called _____________________?
A. Super passage
B. Syphon – Aqueduct
770. An open cut given in a canal bank, suitably protected by stone pitching to the upland drainage water into the canal is called ___________________?
B. Out let