  We explicitly compute the effective resistances between any two vertices of a
prism graph by using circuit reductions and our earlier findings on a ladder
graph. As an application, we derived a closed form formula for the Kirchhoff
index of a prism graph. We show as a byproduct that an explicit sum formula
involving trigonometric functions hold by comparing our formula for the
Kirchhoff index and previously known results in the literature. We also
expressed our formulas in terms of certain generalized Fibonacci numbers.
