Water Resources Engineering - Online Test

Q1. In the water content of a fully saturated soil mass is 100% the void ratio of the sample is
Answer : Option B
Explaination / Solution:
No Explaination.


Q2. The relationship between porosity (η), specific yield (Sy) and specific retention (Sr) of an unconfined aquifer is
Answer : Option A
Explaination / Solution:
No Explaination.


Q3. Ultimate BOD of a river water sample is 20 mg/L. BOD rate constant (natural log) is 0.15 day-1. The respective values of BOD (in %) exerted and remaining after 7 days are: 
Answer : Option C
Explaination / Solution:



Q4.  The velocity components of a two dimensional plane motion of a fluid are

The correct statement is: 
Answer : Option A
Explaination / Solution:



Q5. The average surface area of a reservoir in the month of June is 20 km2. In the same month, the average rate of inflow is 10 m3 /s, outflow rate is 15 m3/s, monthly rainfall is 10 cm, monthly seepage loss is 1.8 cm and the storage change is 16 million m3 . The evaporation (in cm) in that month is
Answer : Option B
Explaination / Solution:



Q6. A plane flow has velocity components u = 1/T1, v = -y/T2 and w = 0 and x, y and z directions respectively, where T1 (≠0) and T2 (≠0) are constants having the dimensions of time. The given flow is incompressible if
Answer : Option D
Explaination / Solution:



Q7. Group I lists a few devices while Group II provides information about their uses. Match the devices with their corresponding use.
 
Answer : Option D
Explaination / Solution:

Aneometer → wind speed Hygrometer → water vapour content of air Pilot tube → flow velocity at a specific point in the flow stream Tensionmeter → Capillary potential of soil water

Q8. A venturimeter having a throat diameter of 0.1 m is used to estimate the flow rate of a horizontal pipe having a diameter of 0.2 m. For an observed pressure difference of 2 m of water head and coefficient of discharge equal to unity, assuming that the energy losses are negligible, the flow rate (in m3 /s) through the pipe is approximately equal to 
Answer : Option C
Explaination / Solution:



Q9. With reference to a standard Cartesian (x, y) plane, the parabolic velocity distribution profile of fully developed laminar flow in x-direction between two parallel, stationary and identical plates that are separated by distance, h, is given by the expression

In this equation, the y = 0 axis lies equidistant between the plates at a distance h/2 from the two plates, p is the pressure variable and µ is the dynamic viscosity term. The maximum and average velocities are, respectively
Answer : Option A
Explaination / Solution:



Q10. A waste water stream (flow = 2 m3 /s, ultimate BOD = 90 mg/l) is joining a small river (flow = 12 m3 /s, ultimate BOD = 5 mg/l). Both water streams get mixed up instantaneously. Crosssectional area of the river is 50 m2 . Assuming the de-oxygenation rate constant, k' = 0.25/day, the BOD (in mg/l) of the river water, 10 km downstream of the mixing point is
Answer : Option C
Explaination / Solution: