  We theoretically investigate the applied magnetic field-angle dependence of
the flux-flow resistivity $\rho_{\rm f}(\alpha_{\rm M})$ for an uniaxially
anisotropic Fermi surface. $\rho_{\rm f}$ is related to the quasiparticle
scattering rate $\varGamma$ inside a vortex core, which reflects the sign
change in the superconducting pair potential. We find that $\rho_{\rm
f}(\alpha_{\rm M})$ is sensitive to the sign-change in the pair potential and
has its maximum when the magnetic field is parallel to the gap-node direction.
We propose the measurement of the field-angle dependent oscillation of
$\rho_{\rm f}(\alpha_{\rm M})$ as a phase-sensitive field-angle resolved
experiment.
