Heat Transfer - GATE practice papers - Mechanical for Q. 371
Q. Two layers of different metals are made composite connecting parallel. The heat flow takes place as shown in figure. Thermal resistances of the two layers are R1 = 0.036 K/W and R2 = 0.05 K/W What is the thermal resistance of the system? (Marks: 02)
- Published on 19 Oct 15a. 0.086 K/W
b. 47.778 K/W
c. 0.0209 K/W
d. none of the above
ANSWER: 0.0209 K/W
In a composite wall when layers are connected in parallel, the thermal resistance of the system is given by,
(1 / R) = (1 / R2) + (1 / R2)
R = (R1 × R2) / (R1 + R2)
R = (0.036 × 0.05) + (0.036 + 0.05)
R = 0.0209 K/W
