JEE MAIN - Physics (2022 - 24th June Morning Shift - No. 18)
Two metallic blocks M1 and M2 of same area of cross-section are connected to each other (as shown in figure). If the thermal conductivity of M2 is K then the thermal conductivity of M1 will be :
[Assume steady state heat conduction]
_24th_June_Morning_Shift_en_18_1.png)
10 K
8 K
12.5 K
2 K
Explanation
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 $${{20} \over {16}} \times K' = {{80} \over 8} \times K$$
$$ \Rightarrow K' = 8\,K$$
Comments (0)
