Normal incidence is also known as which term?

Normal incidence is also known as which term?

• A. Oblique Incidence
• B. Perpendicular Incidence
• C. Lateral Incidence
• D. Acoustic Incidence

Answer: (B)

Incidence is described by how the wave arrives relative to the surface normal. Normal incidence means the wavefront hits the boundary exactly at 90 degrees to the surface, i.e., it is perpendicular to the boundary. That’s why the correct term is perpendicular incidence. Oblique incidence is when the angle isn’t 90 degrees. Lateral incidence isn’t a standard way to describe the angle of arrival and doesn’t specify the geometry. Acoustic incidence refers to the nature of the wave (sound), not the angle of incidence. In normal/incidence problems, using perpendicular (normal) incidence keeps the direction simple and often makes boundary behavior easier to analyze.

Incidence is described by how the wave arrives relative to the surface normal. Normal incidence means the wavefront hits the boundary exactly at 90 degrees to the surface, i.e., it is perpendicular to the boundary. That’s why the correct term is perpendicular incidence.

Oblique incidence is when the angle isn’t 90 degrees. Lateral incidence isn’t a standard way to describe the angle of arrival and doesn’t specify the geometry. Acoustic incidence refers to the nature of the wave (sound), not the angle of incidence. In normal/incidence problems, using perpendicular (normal) incidence keeps the direction simple and often makes boundary behavior easier to analyze.