Same quantity of ice is filled in each of the two metal container P and Q having the same size, shape and will thickness but make of different materials. The containers are kept in identical surroundings, The ice in P melts completely in time t_(1), whereas in Q takes a time t_(2). The ratio of thermal conductivities of hte materials of P and Q is:

Same quantity of ice is filled in each of the two metal container P an

1.	Same quantity of ice is filled in each of the two metal container P and Q having the same size, shape and will thickness but make of different materials. The containers are kept in identical surroundings, The ice in P melts completely in time t_(1), whereas in Q takes a time t_(2). The ratio of thermal conductivities of hte materials of P and Q is:
Answer» `t_(2):t_(1)` `t_(1):t_(2)` `t_(1)^(2):t_(2)^(2)` `t_(2)^(2):t_(1)^(2)` Solution :a) We know that, relation between the temperature gradient (TG) and THERMAL conductivity (K), `(dQ)/(dt) = -KA(d(theta))/(dx)=-KAxx(TG)` i.e., `TG alpha 1/K` `(dQ)/(dt)` = constant or `Kalpha1/t rArrK_(1)ALPHA1/(t_(1))`...........(i) `K_(2)alpha1/t_(2)`..............(II) From the Eqs. (i) and (ii), we get `K_(1)/K_(2)=(1//t_(1))/(1//t_(2)) rArrK_(1):K_(2)=t_(2):t_(1)`