Questions and answers for exam Preparation

MCQs

Total Questions : 153 | Page 1 of 16 pages

Question 1. Calculate the value of minimum base width for an elementary triangular concrete gravity dam supporting 72 m height of reservoir water and full uplift? (Take specific gravity of concrete as 2.4 and coefficient of friction as 0.7)

36.28 m
39.77 m
51.5 m
73.5 m

Discuss Question

Answer: Option D. -> 73.5 m
Answer: (d).73.5 m

Question 2. The two-dimensional stability analysis of gravity dams proves better for U-shaped valleys than for V-shaped valleys.

True
False
May be True or False
Can't say

Discuss Question

Answer: Option A. -> True
Answer: (a).True

Question 3. For usual values of permissible compressive stress and specific gravity of concrete, a high concrete gravity is the one whose height exceeds ______________

48 m
70 m
88 m
98 m

Discuss Question

Answer: Option C. -> 88 m
Answer: (c).88 m

Question 4. When the reservoir is empty, the maximum vertical stress equal to ________________

At heel = 2W/B and at toe = 0
At heel = 0 and at toe = 2W/B
At heel = toe = zero
At heel = toe = 2W/B

Discuss Question

Answer: Option A. -> At heel = 2W/B and at toe = 0
Answer: (a).At heel = 2W/B and at toe = 0

Question 5. For triangular dam section of height H for just no tension under the action of water pressure, self-weight and uplift pressure, the minimum base width required is _____________

H / (S-1)
H / S^1/2
H / (S – 1)⁻¹
H / (S-1)^1/2

Discuss Question

Answer: Option D. -> H / (S-1)^1/2
Answer: (d).H / (S-1)^1/2

Question 6. The axis of a gravity dam is the ______________________

line of the crown of the dam on the downstream side
line of the crown of the dam on the upstream side
centre-line of the top width of the dam
line joining mid-points of the base

Discuss Question

Answer: Option B. -> line of the crown of the dam on the upstream side
Answer: (b).line of the crown of the dam on the upstream side

Question 7. The provision of drainage gallery in a gravity dam helps in reducing ____________________

hydrostatic pressure
seepage pressure
silt pressure
both hydrostatic pressure and seepage pressure

Discuss Question

Answer: Option B. -> seepage pressure
Answer: (b).seepage pressure

Question 8. Which of the following attempts are made to reduce the uplift in order to economize on the provided section of a concrete gravity dam?
i. Providing drainage gallery to collect seepage water
ii. Constructing cut-off under upstream face
iii. Pressure grouting in dam foundation
iv. Provision of shear keys or keyways

i and ii
i, ii and iii
i, ii and iv
i, ii, iii and iv

Discuss Question

Answer: Option B. -> i, ii and iii
Answer: (b).i, ii and iii

Question 9. A concrete gravity dam having a maximum reservoir level at 200 m and the RL of the bottom of the dam 100 m. The maximum allowable compressive stress in concrete is 3000 KN/m² and the specific gravity of concrete is 2.4. Calculate the height of the dam and check whether it is a high dam or low dam.

H = 90 m High gravity dam
H = 90 m Low gravity dam
H = 214.2 m High gravity dam
H = 214.2 m Low gravity dam

Discuss Question

Answer: Option A. -> H = 90 m High gravity dam
Answer: (a).H = 90 m High gravity dam

Question 10. Presence of tail-water in a gravity dam ____________________

increases the principal stress and decreases the shear stress
increases both the principal stress and the shear stress
decreases the principal stress and increases the shear stress
decreases both the principal stress and the shear stress

Discuss Question

Answer: Option D. -> decreases both the principal stress and the shear stress
Answer: (d).decreases both the principal stress and the shear stress