Two identical metal plates are welded end to end as shown in - (i) . `20` cal of heat flows through it in `4` minutes. If the plates are welded as shown in figure-(ii) , find the time (in minutes) taken by the same amount of heat to flow through the plates.

Answer

1 min

Explanation

Rate of heat flow `(DeltaQ)/(Deltat) = (kA(T_(1)-T_(2)))/(l) implies Deltat prop (l)/(A)`