In relation to metal casting defects, match the following
| Defect | Description | ||
| P | Dross | I | Shallow blow found on a flat casting surface |
| Q | Scab | II | Lighter impurities appearing on the top surface of a casting |
| R | Scar | III | A rough, thin layer of metal, protruding above the casting surface, on top of a thin layer of sand |
GATE ME - 2026,
Answer: A
The correct matching is P-II, Q-III, R-I.
Dross consists of lighter impurities, oxides and slag, that float and appear on the top surface of a casting (II). A scab is a rough, thin layer of metal protruding above the casting surface over a thin layer of sand, where the mould face has lifted and metal has run behind it (III). A scar is a shallow blow found on a flat casting surface (I).
Every other option assigns at least one of these definitions to the wrong defect; for example, describing dross as a rough metal layer over sand confuses it with a scab.
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