JEE Main2007PhysicsThermal Properties of MatterActual
One end of a thermally insulated rod is kept at a temperature T₁ and the other at T₂ . The rod is composed of two sections of lengths ₁ and ₂ and thermal conductivities k₁ and k₂ respectively. The temperature at the interface of the two sections is
Options
- A( k ₂ ₂ T ₁+ k ₁ ₁ T ₂ ) / ( k ₁ ₁+ k ₂ ₂ )
- B( k ₂ ₁ T ₁+ k ₁ ₁ T ₂ ) / ( k ₂ ₁+ k ₁ ₂ )
- C( k ₁ ₂ T ₁+ k ₂ ₁ T ₂ ) / ( k ₁ ₂+ k ₂ ₁ )
- D( k ₁ ₁ T ₁+ k ₂ ₂ T ₂ ) / ( k ₁ ₁+ k ₂ ₂ )
Correct answer
C. ( k ₁ ₂ T ₁+ k ₂ ₁ T ₂ ) / ( k ₁ ₂+ k ₂ ₁ )
Step-by-step solution
( T ₁- T ) k ₁ ₁ = ( T - T ₂ ) k ₂ ₂ ~T = T ₁ k ₁ ₂+ T ₂ k ₂ ₁ k ₁ ₂+ k ₂ ₁