Home/
Competitive Exams/
JEE Main & Advanced/
Physics/
Elasticity, Thermal Expansion, Calorimetry and Heat Transfer/
Question 30872
JEE Physics · Hard

Elasticity, Thermal Expansion, Calorimetry and Heat Transfer: Conduction MCQ

Solve this quality-checked JEE multiple-choice question, then review the correct answer and explanation.

Timer-based practiceDetailed answer reviewMobile-friendly flow
ConductionHardQuestion 30872

Question

A composite wall has two layers (L₁ = L₂ = 0.1 m, k₁ = 0.5, k₂ = 1.0 W/m·K). Temperature across wall = 100°C. Heat flux (Q/A) is:
  1. A
    333 W/m²
    Correct
  2. B
    500 W/m²
  3. C
    667 W/m²
  4. D
    250 W/m²

Correct answer

333 W/m²

Explanation

Total resistance per unit area: L₁/k₁ + L₂/k₂ = 0.1/0.5 + 0.1/1 = 0.2 + 0.1 = 0.3 m²·K/W. Heat flux = 100/0.3 ≈ 333 W/m².

Review Elasticity, Thermal Expansion, Calorimetry and Heat Transfer notesStart timed chapter practice