A stone of 0.36 `m^(2)` cross -sectional area and 0.1 m thickness has its lower surface in contact with water at `100^(@)C` and upper surface in contact with ice at `0^(@)C`. If 4.8 kg ice melting in 1 hour, then what is the thermal conductivity of stone ? Latent heat of fusion of ice is `3.36xx10^(5)" J/kg"`.

Options

A. `1.24" J/ms "^(@)C`
B. `1.29" J/ms "^(@)C`
C. `2.05" J/ms "^(@)C`
D. `1.02" J/ms "^(@)C`

Answer

A

Explanation

`Q=KA((T_(1)-T_(2))/(L))t`
`mL.=KA((T_(1)-T_(2))/(L))t`
`:.K-(mL.xxL)/(A(T_(1)-T_(2))xxt)`
`=(4.8xx3.36xx10^(5)xx0.1)/(0.36(100-0)xx3600)`
`=1.24" J/ms "^(@)C`