a) 600 kN
b) 500 kN
c) 800 kN
d) 1000 kN
Answer: c
2. The factor of safety against overturning generally varies between ___________
a) 2 to 3
b) 1.5 to 2
c) 0.5 to 1.5
d) 1 to 2
Answer: a
3. A sloping apron is provided partly above the river bed and partly below the river bed in case of ____________________________
a) When TWC coincides with the JHC at all discharges
b) When TWC lies above the JHC at all discharges
c) When TWC lies below the JHC at all discharges
d) When TWC lies above the JHC at low discharges and below the JHC at high discharges
Answer: d
4. When the crest of an ogee spillway is designed to be in accordance with the lower nappe of a free-falling water jet over a duly ventilated sharp-crested weir then theoretically
a) The pressure on the spillway crest will be zero at design head only
b) The pressure on the spillway crest will always be zero
c) The pressure on the spillway crest will always be negative
d) The pressure on the spillway crest will be always positive
Answer: a
5. When the tail-water depths in the river downstream of a spillway are quite low such that the tail-water curve at all discharges lies below the post jump depth curve, then the energy dissipation can be affected best by ___________________
a) A roller bucket
b) A ski-jump bucket
c) Either roller or ski-jump bucket
d) A sloping apron
Answer: b
6. When the TWC lies below the JHC at all discharges, the problem can be solved by which of the following provisions?
i. Constructing a slopping apron above the river bed
ii. Provision of roller bucket type of energy dissipater
iii. Provision of a ski-jump bucket
iv. A slopping apron below the river bed
v. Construction of a subsidiary dam
vi. A sloping apron partly above and partly below the river bed
a) i, iii and v
b) i, ii and vi
c) iii, iv and v
d) i, iii, iv and v
Answer: c
7. Standard stilling basin is provided at the toe of a dam spillway for energy dissipation is usually provided with auxiliary devices like chute blocks and dentated sills for the basic purpose of reducing the length of the stilling basin from about ________________
a) 6 y2 to 4 y2
b) 4 y2 to 2 y2
c) 6 y2 to 2 y2
d) 3 y2 to y2
Where y2 is the post jump depth
Answer: a
8. An ogee spillway of a concrete gravity dam having FRL of 328 m and MWL of 340 m is provided with vertical gates between piers erected on the spillway. The effective length of the spillway is 60 m. The discharge through the spillway when gates are opened up to the actual reservoir level of 331.0 m will be_____________
a) 850 cumecs
b) 1700 cumecs
c) 2800 cumecs
d) 1000 cumecs
Answer: b
9. For a saddle siphon, the maximum operative head is 4.53 m. The width and height of the throat of the siphon are 5 m and 2.25 m respectively. The coefficient of discharge is 0.90. How many units are required to pass a flood of 350 cumecs? (Assume g = 10 m/s2)
a) One
b) Two
c) Three
d) Four
Answer: d
10. Calculate the effective length of the spillway which consists of 6 spans having a clear width of 10 m each. The thickness of each pier may be taken as 2.5 m and the total design head on the crest including velocity head is 16.3 m. Assuming 90° cut water nose piers and rounded abutments.
a) 55 m
b) 60 m
c) 65 m
d) 75 m
Answer: a
11. The downstream apron of the ogee spillway is found to have a negligible effect on the coefficient of discharge when the value of ________________
a) (Hd + d) / He is less than 1.7
b) (Hd + d) / He exceeds 1.7
c) (Hd + d) / He is equal to 1
d) (Hd + d) / He is less than 1.33
where d is the tailwater depth, Hd is the design head and He is the Design head including the velocity head.
Answer: b
12. The W.E.S downstream profile of an ogee spillway can be represented by an equation:
Xn = K Hd n-1. Y
Where x and y are the coordinates of the points on the crest profile and K and n for a vertical upstream spillway would respectively be___________________
a) 2.0 and 1.85
b) 0.5 and 1.85
c) 2.0 and 0.85
d) 0.5 and 0.85
Answer: a
13. Which weir is now extensively used especially on pervious foundations?
a) Vertical drop masonry weir
b) Rock-fill weirs with sloping aprons
c) Concrete weirs with sloping glacis
d) Non-gravity weirs
Answer: c
14. Which of the following statement is incorrect about Non-gravity weir?
a) The weir floor is designed continuous with the divide piers as a reinforced structure
b) The weight of the concrete slab balances the uplift pressure
c) The weight of the divide piers also keep the structure against uplift
d) Brick piers have to be used in place of RCC
Answer: d
15. for the Khosla’s theory of the independent which factor are required
a) floor has a negligible thickness
b) there is only one sheet pile line
c) the floor is horizontal
d) All of these
Answer: d
for more updates and study material follow our site on top right corner 👉
No comments:
Post a Comment