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.

Explanation

Toughness is the ability of a material to absorb energy and deform plastically without fracturing.

It combines strength and ductility, indicating resistance to fracture under impact.

Toughness measures energy absorption before failure.

Explanation

Dimensional quantities have units; shear stress has units of pressure (N/m² or Pa).

Shear stress is a dimensional physical quantity with SI units of pressure.

Explanation

Steel is most elastic among the rubber, steel, glass and sponge.

Steel having the most steep linear stress-strain curve among all.

A stiffer material will have a higher elastic modulus.

Explanation

Friction depends on surface roughness and nature of materials; wet surfaces reduce friction.

Rubber on wet concrete has a much lower friction coefficient compared to dry or metallic surfaces.

Wet surfaces reduce friction significantly.

Explanation

Apparent weight = Normal force; when a lift accelerates downward, the normal force decreases.

If the lift moves downward with acceleration a, apparent weight = W−ma, which is less than the real weight.

Downward acceleration reduces apparent weight.