Match List-I (Pump Type) with List-II (Typical Use) and select the correct code:

Question

Match List-I (Pump Type) with List-II (Typical Use) and select the correct code:

List-I

i. Centrifugal

ii. Reciprocating

iii. Diaphragm

iv. Pneumatic

List-II

a. Viscous sludge

b. Raw sewage

c. Small-scale lifting

d. Dosing chemicals

Choose the correct match:

1. A. i-b, ii-a, iii-d, iv-c (Correct answer)
2. B. i-a, ii-b, iii-c, iv-d
3. C. i-b, ii-d, iii-c, iv-a
4. D. i-c, ii-a, iii-b, iv-d

Correct Answer

Option A — i-b, ii-a, iii-d, iv-c

Detailed Solution & Explanation

The correct answer is i-b, ii-a, iii-d, iv-c.

Key Points

• Each pump type is matched to the fluid it handles well:
  • i. Centrifugal - b. Raw sewage. Open or non-clog impellers pass solids, and the pump moves large volumes at moderate head.
  • ii. Reciprocating - a. Viscous sludge. A positive-displacement pump develops high pressure and handles thick, viscous material that a centrifugal pump cannot.
  • iii. Diaphragm - d. Dosing chemicals. The flexible diaphragm isolates the liquid from moving parts, giving accurate, small, corrosion-free metered doses.
  • iv. Pneumatic ejector - c. Small-scale lifting, typically from a basement or isolated low-lying property.

Additional Information

• The underlying division is between rotodynamic pumps (centrifugal), which impart velocity that is then converted to pressure, and positive-displacement pumps (reciprocating, diaphragm), which trap a fixed volume and force it onward.
• Positive-displacement pumps deliver a nearly constant discharge regardless of head, which is precisely what chemical dosing requires; a centrifugal pump's discharge falls as head rises.
• A pneumatic ejector has no impeller at all — compressed air displaces sewage from a sealed receiver — so nothing can clog, which is why it survives in awkward small applications.
• The recurring exam distractor is pairing reciprocating pumps with raw sewage; their valves and close clearances foul on rags almost immediately.