Answer: limits the overall flow.
- A limits the overall flow
- B boosts the overall flow
- C has no effect at all
- D reverses the heat flow
Correct answer: A. limits the overall flow
Explanation: In series, the poorer conductor acts as a bottleneck, restricting the heat current.
During a phase change (melting or boiling), temperature stays constant while heat is absorbed entirely as latent heat (Q=mL); temperature only rises again once the substance is fully in its new phase.
Concept context
Temperature scales, thermal expansion, calorimetry, and the three modes of heat transfer including radiation laws.