Properties Of Solids And Liquids Question 447
Question: A slab of stone of area $ 0.36 m^{2} $ and thickness 0.1 m is exposed on the lower surface to steam at$ 100{}^\circ C $ . A block of ice at $ 0{}^\circ C $ rests on the upper surface of the slab. In one hour 4.8 kg of ice is melted. The thermal conductivity of slab is: (Given latent heat effusion of ice $ =3.36\times 105 J $
$ {{kg}^{-1}} $ .):
Options:
A) $ 1.24J/m{}^\circ C $
B) $ 1.29J/m{}^\circ C $
C) $ 2.05J/m{}^\circ C $
D) $ 1.02J/m{}^\circ C $
Show Answer
Answer:
Correct Answer: A
Solution:
[a] $ \frac{dQ}{dt}=\frac{KA( 100-0 )}{1}=m\frac{dL}{dt}, $
$ \frac{K\times 100\times 0.36}{0.1}=\frac{4.8\times 3.36\times 10^{5}}{60\times 60} $
$ =1.24J/m/s/{}^\circ C $
