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 :

One end of a copper rod of length 1.0m and area of cross-section 10^(-

1.	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 :
Answer» `8xx10^(-3)` kg `9.2xx10^(-3)` kg `5.4xx10^(-3)kg` `6.9XX10^(-3)`kg Solution :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).

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