Question

The exact solution of the partial differential equation varies from the exact solution of the discretized equations by ___________

(a) truncation error

(b) discretization error

(c) iteration error

(d) modelling error

The question was posed to me in a national level competition.

Enquiry is from Errors in Finite Difference Approximations topic in portion Finite Difference Methods of Computational Fluid Dynamics

Answer 1

The correct choice is (b) discretization error

To explain I would say: The difference between the exact solution of the partial differential equation and the solution of the algebraic equation is the discretization error. Mathematically

Φ=Φnum+∈d

Where,

Φ → Exact solution

Φnum → Numerical solution

∈d → Discretization error