The effectiveness of a fin will be maximum in an environment with

Explanation:

How effectively a fin can enhance heat transfer is characterized by the fin effectiveness, e, which is the ratio of fin heat transfer and the heat transfer without the fin. Effectiveness of the fin is given by

\({\varepsilon _{fin}}\; = \;\surd \left( {\frac{{KP}}{{hA}}} \right)\)

Hence, \({\varepsilon _{fin}}\;\alpha \frac{1}{h}\) 

Since h_{forced conv} > h_{free conv}

Hence, Effectiveness of the fin will be more in free convection than forced convection.