Concept:Changing the shape of a material by melting and recasting does not change intrinsic properties like density or specific heat capacity, but it can change properties that depend on dimensions, such as electrical resistance.
Explanation:When the steel bar is melted and recast into a cube, its mass remains unchanged.
After cooling to the original temperature, the steel has the same density and total volume as before.
Thus, density and volume do not alter.
Specific heat capacity is a material property that depends only on the substance, not on its shape.
However, electrical resistance depends on the conductor's geometry:
R=ρAl, where
l is length and
A is cross-sectional area.
A long bar has a large
l and small
A, while a cube has a smaller effective length and a larger cross-sectional area.
So the value of
R changes after recasting.
Answer:D. electrical resistance