Physics · Grades 7–10
Reflection and the normal · Revision sheet
Measure angles from a perpendicular reference line, not from the mirror.
Learn the idea
Normal
The normal is perpendicular to the reflecting surface at the point where the ray meets it.
Law
The angle of incidence equals the angle of reflection, measured from the normal.
Plane mirror
A plane mirror forms a virtual image the same perpendicular distance behind it as the object is in front.
Visible versus virtual
A virtual image can be seen because rays reach the eye, but those rays do not actually converge behind the mirror.
Explain without looking
- What does virtual mean for a plane-mirror image?
- An object is 2 m from a plane mirror. Find distance between object and image.
Further reading and review references
These are reference links, not copied exercises, institutional endorsement or proof of independent review.
Independent educational review required. Grade bands are approximate; these are not officially aligned curricula.