Heat-Flow Practice: Series Layer Resistances

Heat-Flow Practice: Series Layer Resistances

Original quantitative learning practice in English. All 24 questions are included. Four supplied cases exercise six related calculation targets; they form one topic, not four separate tests. Every question includes the complete initial data. Use the stated model and retain intermediate precision. Choose one answer. Learning target: 20/24, not an official pass mark. This bank covers the calculation topic in its title; it is not a complete professional examination, design approval or operating instruction.
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Two flat layers have thicknesses 0.07 and 0.11 m and supplied conductivities 0.2 and 0.04 W/(m·K). Area is 18 m²; boundary temperature difference is 35 K. Use per-area resistance R=d/k, add the two resistances, then heat flux=ΔT/Rtotal and heat rate=flux×area. Ignore surface resistances and all lateral losses. Calculate the second-layer resistance in m²·K/W. Keep intermediate values unrounded; round the final result to four decimal places if necessary.