Question

Write the sequence in increasing order of average discharge of the following water lifting devices.
A. Persian wheel
B. Water wheel
C. Don
D. Rope and bucket lift

• A. A, B, C, D
• B. A, C, B, D
• C. D, C, A, B
• D. C, B, A, D

Hint:

To rank water lifting devices, consider the power source and continuity of operation. Manual, intermittent methods (bucket) are lowest. Manual, continuous-action methods (Don) are next. Animal-powered, continuous methods (Persian wheel) are higher. Water-powered, continuous methods (Water wheel) are typically the highest of these traditional options.

Answer 1

The Correct Option is C

Step 1: Estimate the typical discharge for each device.
These are traditional, low-power water lifting devices. Their discharge depends on size, power source (human/animal), and lift height.
- D. Rope and bucket lift: This is a manual method, lifting one bucket at a time. It has the lowest discharge, typically less than 1 liter/second.
- C. Don (or Dhoon): A manually operated canoe-shaped scoop, pivoted to lift water over a low bund. It's more efficient than a bucket but still has a low discharge, around 2-5 L/s for low lifts.
- A. Persian wheel: An animal-powered device using a continuous loop of buckets. It provides a continuous flow and has a moderate discharge, typically in the range of 5-10 L/s.
- B. Water wheel: This term is broad, but typically refers to a wheel powered by flowing water to lift water (e.g., a noria). If well-designed, it can have a significant and continuous discharge, often greater than a Persian wheel, potentially 10-20 L/s or more.
Step 2: Arrange them in increasing order of discharge. Based on the estimates, the order from lowest to highest average discharge is:
Rope and bucket lift \(\rightarrow\) Don \(\rightarrow\) Persian wheel \(\rightarrow\) Water wheel.
This corresponds to the sequence D, C, A, B.