Name three common reinforcing fibers used in composites and a brief trait for each.

• A. Carbon fiber: high stiffness/strength, low density; Glass fiber: cost-effective, good strength; Aramid fiber: high toughness/impact resistance.
• B. Carbon fiber: high thermal conductivity; Glass fiber: very light; Aramid fiber: low toughness.
• C. Carbon fiber: low stiffness; Glass fiber: high density; Aramid fiber: poor impact resistance.
• D. Carbon fiber: inexpensive; Glass fiber: poor strength; Aramid fiber: brittle.

Answer: (B)

When choosing reinforcing fibers for composites, you look at the standout properties each fiber brings. The three very common ones are carbon, glass, and aramid. Carbon fiber is valued for high stiffness and strength while keeping the part light because of its low density. Glass fiber is cost-effective and provides solid strength and stiffness for affordable strength. Aramid fiber offers excellent toughness and impact resistance, helping parts absorb energy and resist damage.

So the best description matches carbon with high stiffness and low density, glass with cost-effectiveness and solid strength, and aramid with high toughness and impact resistance. The other pairings give traits that don’t align with how these fibers are typically characterized.