Deck 4: Hydrology and Water Resources Engineering

Question 1

Assertion A : To estimate the rainfall over a catchment, the number of raingauges required per unit area is large for hilly areas.Reason R : Rainfall gradient is steep.Select your correct answer according to the coding system given below :

A)Both A and R are true and R is the correct explanation of A
B)Both A and R are true but R is not the correct explanation of A
C)A is true but R is false
D)A is false but R is true

Answer 1

Both A and R are true and R is the correct explanation of A

Question 2

When surface of transpiration is submerged under water, then potential evapotranspiration is

A)much more than evapotranspiration
B)much less than evapotranspiration
C)equal to evapotranspiration
D)equal to or less than evapotr

Answer 2

much more than evapotranspiration

Question 3

Unit of runoff in M.K.S. system is

A)cubic metre/sec
B)metre/sec
C)cubic metre
D)square metre

Answer 3

cubic metre/sec

Question 4

The runoff increases with

A)increase in intensity of rain
B)increase in infiltration capacity
C)increase in permeability of soil
D)all of the above

Question 5

The area between the isohyets 45 cm and 55 cm is 100 square km and between 55 cm and 65cm 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

Question 6

A current meter is used to measure the

A)velocity of flow of water
B)depth of flow of water
C)discharge
D)none of the above

Question 7

If it rains between 2 P.M. and 3 P.M. and the entire basin area just starts contributing water at 3 P.M. to the outlet, then time of concentration will be

A)15 minutes
B)20 minutes
C)30 minutes
D)60 minutes

Question 8

The rainfall on five successive days were measured as 100 mm, 80 mm, 60 mm, 40 mm and 20 mm respectively. If the infiltration index or the storm loss rate for the catchment area is earlier estimated as 50 mm/day, the total surface run off will be

A)50 mm
B)60 mm
C)90 mm
D)140 mm

Question 9

The normal annual precipitation at stations X, A, B and C are 700 mm, 1000 mm, 900 mm and 800 mm respectively. If the storm precipitation at three station A, B and C were 100 mm, 90 mm and 80 mm respectively, then the storm precipitation for station X will be

A)70mm
B)80mm
C)90 mm
D)105 mm

Question 10

The best unit duration of storm for a unit hydrograph is

A)1 hour
B)one-fourth of basin lag
C)one-half of basin lag
D)equal to basin lag

Question 11

The unit hydrograph due to a storm may be obtained by dividing the ordinates of the direct runoff hydrograph by

A)direct runoff volume
B)period of storm
C)total rainfall
D)none of the above

Question 12

The unit hydrograph of a specified duration can be used to evaluate the hydrograph of storms of

A)same duration only
B)same and shorter duration
C)same and longer duration
D)any duration

Question 13

S-hydrograph is used to obtain unit hydrograph of

A)shorter duration from longer duration
B)longer duration from shorter duration
C)both (a) and (b)
D)none of the above

Question 14

The relation between probability (P) and recurrence interval (T) is given by

A)PT = 1
B)PT² = 1
C)P/T = 1
D)P/T² = 1

Question 15

Dimensions of coefficient of transmissibility are

A)M°L°T°
B)rvfL'T"1
C)M° L2 T1
D)M'LV

Question 16

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

Question 17

An artesian aquifer is the one where

A)water surface under the ground is at atmospheric pressure
B)water is under pressure between two impervious strata
C)water table serves as upper surface of zone of saturation
D)none of the above

Question 18

A deep well

A)is always deeper than a shallow well
B)has more discharge than a shallow well
C)is weaker structurally than a shallow well
D)both (a) and (b)

Question 19

A multipurpose reservoir is the one which is

A)designed for one purpose but serves more than one purpose
B)planned and constructed to serve various purposes
C)both (a) and (b)
D)none of the above

Question 20

The useful storage is the volume of water stored in the reservoir between

A)minimum pool level and maximum pool level
B)minimum pool level and normal pool level
C)normal pool level and maximum pool level
D)river bed and minimum pool level

Question 21

The water stored in the reservoir below the minimum pool level is called

A)useful storage
B)dead storage
C)valley storage
D)surcharge storage

Question 22

For a flood control reservoir, the effective storage is equal to

A)useful storage - valley storage
B)useful storage + surcharge storage
C)useful storage + surcharge storage + valley storage
D)useful storage + surcharge storage -valley storage

Question 23

Trap efficiency of a reservoir is a function of

A)capacity/inflow ratio
B)capacity/outflow ratio
C)outflow/inflow ratio
D)none of the above

Question 24

The total capacity of a reservoir is 25 million cubic metres and dead storage is 5 million cubic metres. If the average volume of sediment deposition is 0.10 million cubic metre per year, then the usefulness of the reservoir will start reducing after

A)50 years
B)150 years
C)200 years
D)250 years

Question 25

The forces, which are considered for the analysis of an elementary profile of a gravity dam under empty reservoir condition, are
i. Water pressure
ii. Self weight
iii. Uplift
iv. Pressure due to earthquake
The correct answer is

A)Only (ii)
B)(i), (ii) and (iii)
C)(i), (ii) and (iv)
D)(i), (ii), (iii) and (iv)