A water sample has a pH of 9.25. The concentration of hydroxyl ions in the water sample is

If a small concrete cube is submerged deep in still water in such a way that the pressure exerted on all faces of the cube is p, then the maximum shear stress developed inside the cube is

The ratio of actual evapo-transpiration to potential evapo-transpiration is in the range

Wheat crop requires 55 cm of water during 120 days of base period. The total rainfall during this period is 100 mm. Assume the irrigation efficiency to be 60%. The area (in ha) of the land which can be irrigated with a canal flow of 0.01 $$m^3/s$$ is