If D is the depth of scour below original bed, then the width of launching apron is generally taken as________________?

Related Mcqs:

1. The maximum average depth due to one day storm over an area of 100 km2 is 100 mm. Depth-Area-Duration (DAD. curves indicate that for the same area of 100 km2 the maximum average depth for a 3 hour storm will be__________________?

   A. 100 mm
   B. more than 100 mm
   C. less than 100 mm
   D. none of the above

2. For wave action in dams, the maximum height of freeboard is generally taken to be equal to_______________?

   A. 0.5 hw
   B. 0.75 hw
   C. 1.25 hw
   D. 1.50 hw

   where hw is height of wave

3. The ratio of average values of shear stresses produced on the bed and the banks of a channel due to flowing water is________________?

   A. less than 1
   B. equal to 1
   C. greater than 1
   D. equal to zero

4. If the R.L’s of canal bed level and high flood level of drainage are 212.0 m and 210.0 m respectively, then cross drainage work will be________________?

   A. aqueduct
   B. superpassage
   C. syphon
   D. syphon aqueduct

5. The area between the isohyets 45 cm and 55 cm is 100 square km and between 55 cm and 65 cm is 150 square km. The average depth of annua! precipitation over the above basin of 250 square km will be__________________?

   A. 50 cm
   B. 55 cm
   C. 56 cm
   D. 60 cm

6. The maximum rainfall depth of 300 mm in 24 hours has a return period of 100 years. The probability of 24 hours rainfall equal to or greater than 300 mm occurring at least once in 10 years is given by_____________?

   A. (0.99)10
   B. 1 – (0.99)10
   C. (0.9)’00
   D. l-(0.9)100

7. The minimum size of stone that will remain at rest in a channel of longitudinal slope S and hydraulic mean depth R is given by______________?

   A. 4RS
   B. 11 RS
   C. 7RS
   D. 15 RS

8. If d is the depth of the aquifer through which water is flowing, then the relationship between permeability k and transmissible T is given by_______________?

   A. T = kd
   B. T = k/d
   C. T= Vkd
   D. k= VTd

9. The depth of water required to bring the soil moisture content of a given soil upto its field capacity is called_________________?

   A. hygroscopic water
   B. equivalent moisture
   C. soil moisture deficiency
   D. pellicular water

10. Optimum depth of kor watering for rice is______________?

    A. 135 mm
    B. 165 mm
    C. 190 mm
    D. 215 mm