The heat loss from a fin is $$6W.$$ The effectiveness of the fin are $$3$$ and $$0.75,$$ respectively. The heat loss (in $$W$$) from the fin, keeping the entire fin surface at base temperature, is ___________________

Biot number signifies the ratio of

Which one of the following configurations has the highest fin effectiveness?

The value of Biot number is very small (less than $$0.1$$), when