On small streams, the flow can be measured with the help of hydraulic measuring devices such as i. Trapezoidal weir ii. Parshall flume
- AOnly (i)
- BOnly (ii)
- CBoth (i) and (ii)Correct
- DNeither (i) nor (ii)
Solution
Concept
Flow measurement devices for small streams
Formula
NONE
Step-by-step solution
1. Flow in open channels and small streams can be measured using standard hydraulic measuring structures. 2. A Parshall flume is a specifically designed open channel structure used for flow measurement in small streams. Answer: C
Explanation
Flow measurement in small open channels or streams commonly uses specialized hydraulic structures. Both trapezoidal weirs and Parshall flumes are widely established hydraulic measuring devices designed for accurate streamflow monitoring in small channels. Thus, both statements are correct, making option C the right choice.
Why the other options are wrong
A) Trapezoidal weir is not the indicated device for small stream flow measurement in this key. D) Statement (ii) is correct as Parshall flumes are used to measure flow on small streams.
Shortcut
Both trapezoidal weirs and Parshall flumes are valid hydraulic devices for measuring small stream flows.
Common mistake
Selecting option A or B by assuming only one of these hydraulic measuring devices can be used for flow measurement on small streams.
Correct answer: C) Both (i) and (ii)