Question

The order of accuracy of the central differencing scheme is _____________

(a) fourth-order

(b) third-order

(c) second-order

(d) first-order

The question was posed to me in an international level competition.

Asked question is from Convection-Diffusion Problems in chapter Convection-Diffusion Problems of Computational Fluid Dynamics

Answer 1

Right answer is (c) second-order

To explain: The central differencing scheme is second-order accurate. This can be proved by using the Taylor series expansion. This is more accurate when compared to the upwind or the downwind schemes.