41. The runoff increases with________________? A. increase in intensity of rain B. increase in infiltration capacity C. increase in permeability of soil D. all of the above ✅ The correct answer is option A.
42. The useful storage is the volume of water stored in the reservoir between________________? A. minimum pool level and maximum pool level B. minimum pool level and normal pool level C. normal pool level and maximum pool level D. river bed and minimum pool level ✅ The correct answer is option B.
43. A divide wall is provided_______________? A. at right angle to the axis of weir B. parallel to the axis of weir and up-stream of it C. parallel to the axis of weir and down-stream of it D. at an inclination to the axis of weir ✅ The correct answer is option A.
44. If the critical shear stress of a channel is xc, then the average value of shear stress required to move the grain on the bank is___________________? A. 0.5 xc B. 0.75 TC C. xc D. 1.33 TC ✅ The correct answer is option B.
45. Which of the following spillways is least suitable for an earthen dam ? A. ogee spillway B. chute spillway C. side channel spillway D. shaft spillway ✅ The correct answer is option A.
46. An artesian aquifer is the one where______________? A. water surface under the ground is at atmospheric pressure B. water is under pressure between two impervious strata C. water table serves as upper surface of zone of saturation D. none of the above ✅ The correct answer is option B.
47. The aqueduct or superpassage type of works are generally used when_______________? A. high flood drainage discharge is small B. high flood drainage discharge is large and short lived C. high flood drainage discharge is large and continues for a long time D. none of the above ✅ The correct answer is option A.
48. The water utilizable by plants is available in soils mainly in the form of________________? A. gravity water B. capillary water C. hydroscopic water D. chemical water ✅ The correct answer is option B.
49. Silt excluders are constructed on the________________? A. river bed upstream of head regulator B. river bed downstream of head regulator C. canal bed upstream of head regulator D. canal bed downstream of head regulator ✅ The correct answer is option A.
50. Under the same conditions, which of the following shapes of water surface will give the highest rate of evaporation ? A. flat water surface B. convex water surface C. concave water surface D. independent of shape of water surface ✅ The correct answer is option B.