Explanation

Sulphur forms manganese sulphide inclusions, which act as lubricants during cutting.

This reduces tool wear and improves the ease of machining steel.

Sulphur improves the machinability of steel.

Explanation

Normalizing involves heating steel above its critical temperature and then cooling it in air to refine grain structure.

It improves mechanical properties like strength and toughness.

Steel is air-cooled during normalizing, not in furnace or water.

Explanation

Cold working induces internal stresses and hardens the metal; annealing softens it and relieves these stresses.

The process involves heating the metal to a specific temperature and then cooling it slowly.

Explanation

Mild steel contains 0.15% to 0.30% carbon, making it soft and ductile.

It is easily weldable and widely used in construction and manufacturing.

Mild steel = Low carbon steel with high ductility.

Explanation

Silicon encourages carbon in cast iron to precipitate as graphite rather than combined carbide.

This improves machinability and reduces brittleness in cast iron.

Silicon promotes graphite formation in cast iron.

Explanation

The nature of pig iron (basic or acidic) depends on the chemical composition of the slag used in the furnace.

Basic pig iron contains basic oxides like CaO, while acidic pig iron contains acidic oxides like SiO₂.

Slag composition determines whether pig iron is basic or acidic.

Explanation

Ductility is the ability of a material to be stretched into a wire without breaking.

Gold can be drawn into extremely thin wires, more so than tin, lead, or copper.

Gold has the highest ductility among common metals.

Explanation

In a simply supported beam, the bending moment is highest directly under the point of maximum load.

The position of maximum bending shifts toward the heavier load when the loads are unequal.

Maximum bending occurs beneath the heavier concentrated load.

Explanation

Impact strength measures the energy a material can absorb during sudden loading without fracturing.

It reflects both the strength and ductility of the material.

Higher impact strength indicates higher toughness.

Explanation

The ultimate stress point represents the maximum stress a material can withstand before necking begins.

Beyond this point, the specimen’s cross-section starts reducing until fracture.

Necking begins at the ultimate stress point on the stress-strain curve.