Civil Engg (Practice Tests)

1. Which type of plume may occur during winter nights?
(a) Looping
(b) Inversion
(c) Coning
(d) Lofting
Ans. (d)
2. A machine in a steel plate fabricating industry is found to be producing a sound level of 50 dB. In the expansion plans one more such machine needs to be added. What will be the combined noise level?
(a) 80—100 dB
(b) 101—150 dB
(c) 51—70 dB
(d) 40—50 dB
Ans. (c)
3. A rectangular channel 3 wide is laid on a slope of 0.0002. When the depth of flow in the channel is .l m, what is the average boundary shear stress (nearly)?
(a) 0.3 N/m2
(b) 0.15 N/m2
(c) 3.0 N/m2
(d) 1.5 N/m2
Ans. (d)
4. A river model is constructed to a horizontal scale of 1:1000 and a vertical scale of 1: 100. A model discharge of 0.1 m3 /s would correspond to a discharge in the prototype of what magnitude?
(a) 102 m3 /s
(b) 103 m3 /s
(c) 104 m3 /s
(d) 105 m3 /s
Ans. (d)
5. In the model of a highway bridge constructed to a scale of 1: 25, the force of water on the pier was measured as 5N. What is the force (approximate) on the prototype pier?
(a) 15.6kN
(b) 25.3kN
(c) 78kN
(d) 90kN
Ans. (c)
6. A circular pipe of radius R carries a laminar flow of a fluid. The average velocity is indicated as the local velocity at what radial distance, measured from the centre?
(a) 0.50R
(b) 0.71R
(c) 0.67 R
(d) 0.29 R
Ans. (b)
7. A rectangular channel is 6 m wide and discharges 30 m3 s-1. The upstream depth is 2.0 m, acceleration due to gravity is 10 m s-2. Then, what is the specific energy (approximate)?
(a) 2.5
(b) 0.3
(c) 2.3
(d) None of the above
Ans. (c)
8. Flow depths across a sluice gate are 2.0 m and 0.5 m. What is the discharge (perimeter width)?
(a) 1.0 m2/s
(b) 1.4 m2/s
(c) 2.0 m2/s
(d) 2.8 m2/s
Ans. (d)
9. A right-angled triangular channel, symmetrical in section about the vertical, carries a discharge of 5 m3/s with a velocity of 1.25 m/s. What is the approximate value of the Froude number of the flow?
(a) 0.3
(b) 0.4
(c) 0.5
(d) 0.6
Ans. (b)
10. Consider the following statements associated with groynes:
1. Hydraulic behaviour of a system of groynes is influenced by the characteristics of particles that constitute the littoral drift.
2. Groyne is constructed approximately parallel to shore. Which of the statements given above is/are correct?
(a) 1 only
(b) 2 only
(c) Both 1 and 2
(d) Neither 1 nor 2
Ans. (a)