A common disadvantage of solid conductors is:

• A. More expensive to manufacture
• B. More susceptible to fatigue under vibration
• C. Higher insulation thickness required
• D. Lower conductivity than stranded of same cross-section

Answer: (B)

When a conductor is exposed to vibration, how it handles repeated bending matters. A solid conductor is a single, stiff strand, so it doesn’t flex easily. Under continuous vibration, stress concentrates at bends and terminations, leading to microscopic cracks that accumulate with cycles and cause metal fatigue. Stranded conductors, made of many small strands bound together, can flex more easily; the stress is distributed among the individual strands, reducing the tendency for fatigue and damage over time. That flexibility under vibration is why solid conductors are commonly more susceptible to fatigue in such conditions.

The other statements aren’t general disadvantages of solid conductors. Manufacturing cost isn’t inherently higher for solid conductors; insulation thickness is driven by voltage and environment rather than whether the conductor is solid or stranded; and conductivity for the same cross-sectional area is essentially the same, since the material is the same.