One end of a copper rod of length `1.0m` and area of cross-section `10^(-3)m^(2)` is immersed in boiling water and the other ens in ice. If the coefficient of thermal conductivity of copper is 92 cal/m-s- `""^(@)C` and the latent heat of ice is `8xx10^(4)` cal/kg, then the amount of ice which will melt in one munite is :

Options

A. `8xx10^(-3)` kg
B. `9.2xx10^(-3)` kg
C. `5.4xx10^(-3)kg`
D. `6.9xx10^(-3)`kg

Answer

D

Explanation

Here `dQ=mL`
where L is latent heat and `t=1` minute.
`(KA(T_(1)-T_(2)))/(l)=mL`
`m=(92xx10^(-3)xx(100-0)60)/(1xx8xx10^(4))`
`=6*9xx10^(-3)kg`
Correct choice is (d).