Question

For an algebraic multi-grid approach, the residual in the k^th level is __________

(a) residual in the (k+1)^th level

(b) summation of the residuals in the (k)^th level

(c) residual in the (k-1)^th level

(d) summation of the residuals in the (k-1)^th level

I got this question in final exam.

The question is from Numerical Methods topic in chapter Numerical Methods of Computational Fluid Dynamics

Answer 1

Correct choice is (d) summation of the residuals in the (k-1)^th level

Easy explanation: While transferring the errors from one level to another, the residual of the k^th level is given by the summation of the residuals of all the terms in the previous (k-1)^th level.