Question 294: Thermodynamics & KTG

Question

Two metallic blocks M
1
and M
2
of same area of cross-section are connected to each other (as shown in figure). If the thermal conductivity of M
2
is K then the thermal conductivity of M
1
will be :
[Assume steady state heat conduction]
![](https://app-content.cdn.examgoal.net/fly/@width/image/1l5d0jq7f/876420af-7536-40e3-8f66-9601a3446fa0/07e983b0-ff0b-11ec-ad5a-f526c2c01ae4/file-1l5d0jq7g.png?format=png)

Accepted Answer

Thermal current is same so
${{dQ} \over {dt}} = {{\Delta {T_1}} \over {{{{I_1}} \over {{K_1}A}}}} = {{\Delta {T_2}} \over {{{{I_2}} \over {{K_2}A}}}}$
or ${{20} \over {16}} 	imes K' = {{80} \over 8} 	imes K$
$ \Rightarrow K' = 8\,K$

Answer

10 K

Answer

8 K

Answer

12.5 K

Answer

2 K

Thermodynamics & KTG

Two metallic blocks M 1 and M 2 of same area of cross-section are connected to each other (as shown in figure). If the thermal conductivity of M 2 is K then the thermal conductivity of M 1 will be : [Assume steady state heat conduction]

Choose the correct answer: