Oblique incidence means ______.

Oblique incidence means ______.

• A. Right angles
• B. Perpendicular
• C. Not at right angles
• D. Oblique

Answer: (C)

Oblique incidence means the ray strikes the surface at an angle that is not a right angle to the surface. In practice, the angle of incidence is measured from the normal (the line perpendicular to the surface). When the incidence is perpendicular, the angle to the surface is 90 degrees (normal incidence). Any other angle means oblique incidence, which matches the description “not at right angles.” The other options describe 90-degree relationships or simply restate the term, which would refer to normal incidence rather than oblique.

Oblique incidence means the ray strikes the surface at an angle that is not a right angle to the surface. In practice, the angle of incidence is measured from the normal (the line perpendicular to the surface). When the incidence is perpendicular, the angle to the surface is 90 degrees (normal incidence). Any other angle means oblique incidence, which matches the description “not at right angles.” The other options describe 90-degree relationships or simply restate the term, which would refer to normal incidence rather than oblique.