Join the Most Relevant JEE Main 2025 Test Series & get 99+ percentile! Join Now
Search any question & find its solution
Question: Answered & Verified by Expert
One end of a thermally insulated rod is kept at a temperature T1 and other at T2. The rod is composed of two sections of lengths l1 and l2 and thermal conductivities K1 and K2 respectively. The temperature at the interface of the two sections is

PhysicsThermal Properties of MatterNEET
Options:
  • A (K2l2T1+K1l1T2)(K1l1+K2l2)
  • B (K2l1T1+K1l2T2)(K2l1+K1l2)
  • C (K1l2T1+K2l1T2)(K1l2+K2l1)
  • D (K1l1T1+K2l2T2)(K1l1+K2l2)
Solution:
1851 Upvotes Verified Answer
The correct answer is: (K1l2T1+K2l1T2)(K1l2+K2l1)
Let temperature at the interface is T.

For part AB,



Q1tT1-TK1l1

For part BC,

Q2tT-T2K2l2

At equilibrium, Q1t=Q2t

T1-TK1l1=T-T2K2l2

       T=T1K1l2+T2K2l1K1l2+K2l1

Looking for more such questions to practice?

Download the MARKS App - The ultimate prep app for IIT JEE & NEET with chapter-wise PYQs, revision notes, formula sheets, custom tests & much more.