Mechanical Engineering - Heat Transfer, Refrigeration and Air Conditioning - Discussion
Discussion Forum : Heat Transfer, Refrigeration and Air Conditioning - Section 5 (Q.No. 31)
31.
A composite slab has two layers of different materials with thermal conductivities k1 and k2. If each layer has the same thickness, then the equivalent thermal conductivity of the slab will be
k1 k2
k1 + k2
Discussion:
10 comments Page 1 of 1.
Harsh said:
5 years ago
Option D is correct.
Since R eq= R1+R2 so substituting the values of R we will get option D.
Since R eq= R1+R2 so substituting the values of R we will get option D.
Gaurav said:
5 years ago
Option C is for equivalent spring deflection. Here the answer is D.
SURU said:
5 years ago
Composite means series.
Total resistance equal to add all.
2x/kA =x/kA+x/kA.
So, answer D is correct.
Total resistance equal to add all.
2x/kA =x/kA+x/kA.
So, answer D is correct.
Debnath said:
5 years ago
dQ = AdT/summation (x/k1 +x/k2).
KAdT/(x+x) = AdT.k1.k2/x(k1+k2).
K/2 = k1k2/(k1+k2).
K = 2k1k2/(k1+k2).
KAdT/(x+x) = AdT.k1.k2/x(k1+k2).
K/2 = k1k2/(k1+k2).
K = 2k1k2/(k1+k2).
(1)
Akash said:
6 years ago
It should be (k1.k2)/(k1+k2).
Joy said:
6 years ago
D is correct.
However, there shouldn't be the 2 in the numerator.
However, there shouldn't be the 2 in the numerator.
Ankit said:
6 years ago
Answer should be K1K2/K1+K2.
Dixit said:
7 years ago
No, K1.k2/k1+k2 is the right option.
Abhilash said:
8 years ago
D is correct. I agree with the Given answer.
Debashis said:
8 years ago
Answer C is correct.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers