Q.
A mirror is inclined at an angle of $\theta $ with the horizontal. Let a ray of light be incident at an angle $\theta $ as shown, then what is the angle made by the reflected ray with the horizontal ?
NTA AbhyasNTA Abhyas 2020
Solution:
For reflection, angle of incidence $$ $i$ = $r$ angle of reflection
$\therefore $ The refelceted ray makes the same angle $\theta $ with the mirror as like the incident ray at the point of incidence on the inclined mirror.
Draw a normal to the inclined mirror, then then incident ray is at an angle $\theta $ with the mirror and at $90^{0}-\theta $ with the normal.
Hence, according to the law of reflection, the reflected ray will be at $90^{0}-\theta $ with the normal and $\theta $ with the inclined mirror.
Thereby, the reflected ray becomes parallel to the horizontal.
For reflection, angle of incidence $$ $i$ = $r$ angle of reflection $\therefore $ The refelceted ray makes the same angle $\theta $ with the mirror as like the incident ray at the point of incidence on the inclined mirror.
Draw a normal to the inclined mirror, then then incident ray is at an angle $\theta $ with the mirror and at $90^{0}-\theta $ with the normal.
Hence, according to the law of reflection, the reflected ray will be at $90^{0}-\theta $ with the normal and $\theta $ with the inclined mirror.
Thereby, the reflected ray becomes parallel to the horizontal.