Thermal Conductivity
- A rod
1.3 m long consists of a 0.8 m length of Aluminium
joined end-to-end to a 0.5 m length of brass. The free end of the aluminium
section is maintained at 150 oC and
the free end of the brass piece is maintained at 20 oC. No heat is lost through the sides of the
rod. In the steady state, what is
the temperature of the point where the two metals are joined
? (Thermal conductivity of
brass = 109 W/mK).
- Rods
of copper, brass and steel are welded together to form a Y-shaped
figure. The cross-sectional area of
each rod is 2 cm2. The
free end of the copper rod is maintained at 100 oC
and the free ends of the brass and steel rods at 0 oC. Assume that there is no heat loss from
the surfaces of the rods. The
lengths of the rods are as follows: copper, 13 cm; brass, 18 cm; steel, 24
cm. (Thermal conductivity of brass
= 109 W/mK).
(a) What is the temperature of the junction point ?
(b) What is the rate of heat flow in each of the rods ?