Transmission Of Heat Question 334
Question: Find the equivalent thermal resistance of combination of rods as shown in figure. Every rod has same length I and cross-sectional area A. Thermal conductivities are mentioned in figure.
Options:
A) $ \frac{1}{4KA} $
B) $ \frac{7l}{4KA} $
C) $ \frac{7l}{12KA} $
D) $ \frac{l}{12KA} $
Show Answer
Answer:
Correct Answer: C
Solution:
[c] $ R _{1}=\frac{l}{KA},R _{2}=\frac{l}{2KA},R _{3}=\frac{l}{4KA} $
$ R _{eq}=( \frac{R _{1}R _{2}}{R _{1}+R _{2}}+R _{3} )=\frac{7l}{12KA} $ [as rods 1 and 2 are in parallel and equivalent is in series with 3].
BETA
