Hydrology and Ground Water

131. The average mean velocity of a stream having depth h, may be obtained by taking the average of the readings of a current meter at a depth of

1. 0.1 h and 0.9 h
2. 0.2 h and 0.8 h
3. 0.3 h and 0.7 h
4. 0.4 h and 0.6 h

View answer

132. The best instrument for measuring the velocity of a stream flow is

1. Pitot tube
2. Price's current meter
3. Surface float
4. Sub-surface float

View answer

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

1. 2
2. 3
3. 4
4. 5

View answer

134. The coefficients of permeability of soils of an unconfined aquifer and another confined aquifer were determined by pumping water from the wells and observing the effect of water table in two test wells at equal distances was found to be equal. The total height of confined aquifer H is given by

1. H = h₂ - h₁
2. H = h₁ - h₂
3. H = h₂ + h₁
4. ½ (h1 + h2)

View answer

135. The critical depth in a channel can be produced

1. By raising the bottom of the channel
2. By lowering the bottom of the channel
3. By decreasing the width of the channel
4. Both (a) and (c) of above

View answer

136. The deficiency in rain catch due to vertical acceleration of air forced upward over the gauge, is

1. Greater for heavy rain
2. Greater for lighter rain
3. Greater for large drops
4. Lesser for small rain drops

View answer

137. The drainage water intercepting the canal can be disposed of by passing the canal below the drainage in

1. Aqueduct and syphon aqueduct
2. Aqueduct and super passage
3. Super passage and canal syphon
4. Level crossing

View answer

138. The Dupuit formula is based on

1. One observation well
2. Two observation wells
3. Three observation wells
4. No observation well

View answer

139. The earthen embankments constructed parallel to the river banks at some suitable distance for flood control, are known as

1. Floods walls
2. Dikes
3. Levees
4. Both (b) and (c)

View answer

140. The efficiency of a pump may be taken as

1. 0.55
2. 0.6
3. 0.65
4. 0.7

View answer