In terms of mechanical robustness, solid conductors are generally:

In terms of mechanical robustness, solid conductors are generally:

• A. More flexible
• B. Less robust to repeated bending
• C. Immune to corrosion
• D. More resistant to thermal expansion

Answer: (B)

Repeated bending introduces cyclic stress that can initiate and grow fatigue cracks in metal. A solid conductor carries bending stress across its entire cross-section; with each flex, the surface alternates between tension and compression, and tiny flaws can become cracks over many cycles. Because there aren’t separate strands to share the load, the material accumulates damage more quickly under repeated bending. Stranded conductors fare better here because many small wires can move a bit relative to each other, spreading the stress and slowing crack growth, which makes them more robust to repeated bending. The other options don’t fit: flexibility is greater in stranded conductors, corrosion resistance depends on the material and environment rather than whether the conductor is solid or stranded, and thermal expansion is a property of the material and temperature change rather than the conductor being solid versus stranded.

Repeated bending introduces cyclic stress that can initiate and grow fatigue cracks in metal. A solid conductor carries bending stress across its entire cross-section; with each flex, the surface alternates between tension and compression, and tiny flaws can become cracks over many cycles. Because there aren’t separate strands to share the load, the material accumulates damage more quickly under repeated bending. Stranded conductors fare better here because many small wires can move a bit relative to each other, spreading the stress and slowing crack growth, which makes them more robust to repeated bending. The other options don’t fit: flexibility is greater in stranded conductors, corrosion resistance depends on the material and environment rather than whether the conductor is solid or stranded, and thermal expansion is a property of the material and temperature change rather than the conductor being solid versus stranded.