99. The best unit period of a unit hydrograph, is equal to basin lag divided by

A.2

B.3

C.4

D.5

100. Bernard's distribution graph is a plot of time on X-axis and

A. run off on they-axis

B. total run off on they-axis

C. percentage of total surface run off on y-axis

D. percentage of total surface run off during uniform time intervals on y-axis

101. If total run off of a basin of 50 hectares is 0.8 cm, the ordinate of Bernard's distribution graph, may be calculated by the formula, where Q is the discharge in cumecs at the given time.

A. y = 50 Q

B. y = 100 Q

C. y = 150 Q

D. y 250 Q

102. An intense rain is falling at a uniform rate of 7.5 cm/hour for a period of 60 minutes on a basin whose areas is 500 hectares. If the average infiltration capacity during the entire rain period is assumed to be 1.5 cm/hr, the maximum run-off rate based on 10 minute peak percentage of 16% from distributing graph of the basin, is

A. 40 cumecs

B. 60 cumecs

C. 80 cumecs

D. 100 cumecs.

103. If the potential infiltration of a water shed having'a soil with fair pasture cover, is 10 cm and rainfall is 12 cm, the direct run off is :

A. 2 cm

B. 3 cm

C. 5 cm

D. 8 cm.

104. Pick up the correct statement from the following :

A. The zone below water table, is called zone of saturation

B. The zone above water table, is called zone of aeration

C. The water which exists in the zone of saturation, is called ground water

D. All the above.

105. Pick up the correct statement from the following :

A. The ratio of total volume of voids in soil aggregates to the total volume of aggregate, is called Porosity

B. Water retained by the interstices due to molecular attraction, is called pellicular water

C. The ratio of volume of water obtained by gravity drainage to the total volume of the materials drained, is called 'yield'

D. All the above.

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