This document provides 15 important questions on vector calculus concepts including directional derivatives, unit normals, solenoidal and irrotational vectors, and verification problems for Gauss's divergence theorem, Green's theorem, and Stokes' theorem. Example problems include finding directional derivatives, unit normals, determining if a vector is solenoidal or irrotational, evaluating line integrals, and verifying the vector calculus theorems for different bounding shapes and regions.