Galvanic cell thermodynamics OF cell||Numerical problem

In a galvanic cell, the half cell with higher potential provides a reducing agent.

Introduction|Redox Reaction|Electrochemical Changes|Electrochemical Cells Or Galvanic Cells|Electrolytic Cell |Galvanic Cell Or Voltaic Cells|Observations|Summary

What is the relationship between Gibbs free energy of the cell reaction in a galvanic cell and the emf of the cell ? When will the maximum work be obtained froma galvanic cell ?