A composite wall consists of two plates A and B placed...

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A composite wall consists of two plates A and B placed in series normal to the flow of heat. The thermal conductivities are k_A and k_B and the specific heat capacities are C_PA and C_PB for plates A and B respectively. Plate B has twice the thickness of plate A. At steady state, the temperature difference across plate A is greater than that across plate B, when

A. C_PA > C_PB

B. C_PA < C_PB

C. k_A < 0.5 k_B

D. k_A > 2 k_B

Answer: Option C

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Comments ( 1 )

Vivekanand Ojha :

5 years ago

Condition : ∆Ta>∆Tb
Given: Plate 'a' ~ Ka, L. Plate 'b'~Kb,2L
Concept:Apply FLHC° [Qa/A]=[Qb/A]
Ka=0.5 Kb [∆Tb/∆Ta]
Implise that: 'Ka' must be less than half times of 'Kb'....
[FLHC°= Fourier Law of Heat Conduction]

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