Irrigation Engineering and Hydrology Test 1

Question 1
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Which of the following is not correct in connection with canal lining?

A
Lining of canal helps in controlling seepage

B
Lining of canal prevents water logging

C
Lined canal has more capacity compared to the unlined canal with same properties

D
Canal lining increases cost of maintenance of canal

Question 2
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The stage - discharge relation in a river during the passage of flood is measured. lf q_f is the discharge at the stage when water surface is failing and q_r is the discharge at the same stage when water surface is rising, then

A
q_f = q_r

B
q_f < q_r

C
q_f > q_rb

D
$\frac{q_{f}}{q_{r}}$ = constant for all stages

Question 3
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The peak of the outflow hydrograph will be smaller than of the inflow hydrograph due to storage effects of a reservoir and this reduction in peak value is called _____

A
Flood routing

B
Peak accentuation

C
Muskingum erect

D
Attenuation

Question 4
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Recorded annual maximum 24-hour rainfall magnitudes at station X are as under:
Year
Rainfall (cm)
1960
12.0
1961
6.0
1962
4.8
1963
7.9
1964
12.0
1965
14.2
1966
13.6
1967
6.0
1968
3.7
1969
2.9

What is the return period, in years, for a 6.0 cm annual rainfall according to Weibull formula?

A
10/7,

B
11/7

C
20/13

D
5/3

Question 5
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Curve A is a 6-h unit hydrograph for a catchment basin and curve B is also a direct runoff hydrograph resulting due to a 6–h rainfall excess of 2.5 cm.
Choose the correct statement:

A
Ordinates of curve A is 2.5 times the ordinates of curve B.

B
Ordinates of curve B is 2.5 times the ordinate of curve A.

C
Timebase for curve A is 2.5 times the time base for curve B.

D
Timebase for curve B is 2.5 times the time base for curve A.

Question 6

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The silt control devices are listed in column 1 with their properties in column 2 in the following table.

Column 1 Silt Control Devices	Column 2 Properties
Silt Excluder	Constructed at little downstream distance from head regulator
Silt Ejector	Constructed at the upstream of the head regulator
	Removes silt from the water before it enters the canal
	Removes silt from the water after it enters the canal

The correct combination is

1-A and 1-D

2-A and 2-C

1-B and 1-D

2-A and 2-D

Question 7
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A storm over a catchment of area 120 hectares had a duration of 12 hours. The direct runoff volume during the event was 3.6 hec-m. If the runoff coefficient of the given catchment is 0.45, then the ϕ_index for the given storm event will be

A
3.88 cm/hr

B
4.16 mm/hr

C
4.67 mm/hr

D
5.25 mm/hr

Question 8
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A water course commands on irrigation area of 500 hectares. The intensity of irrigation of area is 50 percent. The transplantation of rice takes 15 days and the total depth of water required by the crop is 60 cm on the field. The duty of irrigation water (in hectares/cumec, rounded to nearest integral places) for the crop on the field during transportation is ______

A
216-216

B
2164-2161

C
2167-2166

D
2169-2162

Question 9
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A siphon spillway of 4 m width and 1 m depth working with a head of 8 m. Assuming the coefficient of discharge for the spillway as 0.58 and number of spillways as four then the discharge (m³/s) to be allowed through the siphon spillways will be ________.

A
115-118

B
1154-1181

C
1157-1186

D
1159-1182

Question 10
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The annual flood series for a river is available for 21 years. If the observed mean discharge and standard deviations of the flood series are 24000 cumecs and 4000 cumecs respectively, then the reduced variate for the return period of 100 years flood will be _______.

A
4.6-4.61

B
4.64-4.611

C
4.67-4.616

D
4.69-4.612

Question 11
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For a crop with growing season of two month, following data is given:
Month
Mean monthly temp
(in °C)
Monthly % of sunshine hours
September
22
6.8
October
18
7.4
The cumulative effective rainfall in these two months is 5.3 cm and consumptive use coefficient is 0.75. If the leaching requirement for the field is 3 cm, find the net irrigation requirement (in cm) for the crop growth.

A
9.76

B
15.76

C
20.36

D
26.36

Question 12
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The average rainfall for the catchment with the following data is obtained by Theisen polygon method.
Station
Rainfall (cm)
Area (km²)
A
10
0.22
B
12
1.06
C
15
2.34
D
20
4.03
E
25
2.03
The average rainfall depth (in cm) is __________.

A
15.32

B
16.46

C
16.54

D
18.74

Question 13
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An elementary gravity dam is constructed of concrete having density of 24380 N/m³. The limiting height of a low dam without considering the uplift was found to be h₀. And with consideration of full uplift it was h₁. The ratio of h₁ to the h₀ is _____

A
0.71

B
1.40

C
1.00

D
1.18

Question 14
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The piezometric head at bottom of floor is 15 m and the datum is 3 m below the floor bottom. The standing water depth above the floor is 2 m. What is the floor thickness considering the specific gravity of floor material as 2.5?

A
3.0 m

B
4 m

C
5 m

D
6.67 m

Question 15
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A 3-hr unit hydrograph for a catchment is given in the table below. The maximum ordinate and delay in the peak for a 6-hr unit hydrograph will be
Time (hr)
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Ordinate (m³/s)
0
8
13
17
28
33
30
27
24
19
16
13
8
5
3
0

A
66 m³/s and 6 hrs

B
55 m³/s and 6 hrs

C
57 m³/s and 3 hrs

D
28.5 m³/s and 3 hrs.

Question 16
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In a catchment area, four rain gauging stations namely A, B, C and D are installed. Rain gauge C was inoperative for a particular year, during which the rain gauge A, B and D recorded 90 cm, 60 cm and 70 cm depth of precipitation respectively. Estimate the missing rainfall at data (in cm), if the annual average data of four stations A, B, C and D is 60 cm, 75 cm, 80 cm and 100 cm respectively.

A
80-80

B
804-801

C
807-806

D
809-802

Question 17
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The porosity and compressibility of a 7.8 m thick confined aquifer are 0.25 and 1 × 10^-8 m²/N, respectively. The storage coefficient of the aquifer is 6.5 × 10^-4. To release 650 m³ of water from 1 km² of this aquifer, the average decline in the hydraulic head will be _____ m.

A
1.00-1.00

B
1.004-1.001

C
1.007-1.006

D
1.009-1.002

Question 18
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A 24-hour storm occurred over a catchment of 2 km² area and the total rainfall observed was 10 cm. An infiltration capacity curve prepared had the initial infiltration capacity of 1 cm/hr and attained a constant value of 0.3 cm/hr after 15 hours of rainfall with a Horton’s constant k = 5 hr^–1. An IMD pan installed in the catchment indicated a decrease of 0.6 cm in the water level (after allowing for rainfall) during 24 hours of its operation. Other losses were found to be negligible. Determine the runoff volume (in cubic meter) from the catchment. Assume a pan coefficient of 0.75.

A
45500-45900

B
455004-459001

C
455007-459006

D
455009-459002

Question 19
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Electrical conductivity (EC) value of a saturated extract of soil is 13 m.mho/cm. Leaching requirement and depth of the water to be applied in the field is 7.5% and 5.94 mm. The value of consumptive use is ______mm.

A
5.4-5.6

B
5.44-5.61

C
5.47-5.66

D
5.49-5.62

Question 20
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The plan area of a reservoir is 1 km². The water level in the reservoir is observed to decline by 20 cm in a certain period. During this period the reservoir receives a surface inflow of a 10 hectare-meters and 20 hectare-meters are abstracted from the reservoir for irrigation. The pan evaporation and rainfall recorded during the same period are 12 cm and 3 cm respectively. The pan-co-efficient is 0.7. Find the seepage loss from the reservoir during this period in hectare-meter –

A
4.6-4.6

B
4.64-4.61

C
4.67-4.66

D
4.69-4.62

Submit Test

Year	Rainfall (cm)
1960	12.0
1961	6.0
1962	4.8
1963	7.9
1964	12.0
1965	14.2
1966	13.6
1967	6.0
1968	3.7
1969	2.9

Station	Rainfall (cm)	Area (km²)
A	10	0.22
B	12	1.06
C	15	2.34
D	20	4.03
E	25	2.03

Time (hr)	0	1	2	3	4	5	6	7	8	9	10	11	12	13	14	15
Ordinate (m³/s)	0	8	13	17	28	33	30	27	24	19	16	13	8	5	3	0

Irrigation Engi...

Question 1

Lining of canal helps in controlling seepage

Lining of canal prevents water logging

Lined canal has more capacity compared to the unlined canal with same properties

Canal lining increases cost of maintenance of canal

Question 2

qf = qr

qf < qr

qf > qrb

qfqr = constant for all stages

Question 3

Flood routing

Peak accentuation

Muskingum erect

Attenuation

Question 4

10/7,

11/7

20/13

5/3

Question 5

Ordinates of curve A is 2.5 times the ordinates of curve B.

Ordinates of curve B is 2.5 times the ordinate of curve A.

Timebase for curve A is 2.5 times the time base for curve B.

Timebase for curve B is 2.5 times the time base for curve A.

Question 6

1-A and 1-D

2-A and 2-C

1-B and 1-D

2-A and 2-D

Question 7

3.88 cm/hr

4.16 mm/hr

4.67 mm/hr

5.25 mm/hr

Question 8

216-216

2164-2161

2167-2166

2169-2162

Question 9

115-118

1154-1181

1157-1186

1159-1182

Question 10

4.6-4.61

4.64-4.611

4.67-4.616

4.69-4.612

Question 11

9.76

15.76

20.36

26.36

Question 12

15.32

16.46

16.54

18.74

Question 13

0.71

1.40

1.00

1.18

Question 14

3.0 m

4 m

5 m

6.67 m

Question 15

66 m3/s and 6 hrs

55 m3/s and 6 hrs

57 m3/s and 3 hrs

28.5 m3/s and 3 hrs.

Question 16

80-80

804-801

807-806

q_f = q_r

q_f < q_r

q_f > q_rb

$\frac{q_{f}}{q_{r}}$ = constant for all stages

66 m³/s and 6 hrs

55 m³/s and 6 hrs

57 m³/s and 3 hrs

28.5 m³/s and 3 hrs.