Three rods of identical area of cross-section and
made from the same metal form the sides of an
isosceles triangle ABC , right angled at B. The
points A and B are maintained at temperatures
T and √2T respectively. In the steady state the
temperature of the point C is Tc. Assuming that
only heat conduction takes place, TCT is equal to
∵ Tb>TA⇒ Heat will flow B to A via two paths
(i) B to A (ii) and along BCA as shown.
Rate of flow of heat in path BCA will be same
i.e (Qt)BC = (QT)CA
⇒ k(√2T − TC)Aa = k(Tc − T)A√2a
⇒TcT = 31 + √2