Handout 1.2

Question 1

Describe the phenomenon that is reflection.

Answer 1

When a light ray falls on a smooth surface, it bounces off.

Question 2

The angle of incidence i and the angle of reflection r are ________________________________________, not ________________________.

Answer 2

measured from the normal, the mirror

Question 3

The normal is ______________________________ which is _________________________________.

Answer 3

an imaginary, dotted line, perpendicular to the mirror

Question 4

The angle of deviation is ___________________________________________. What is its formula?

Answer 4

the angle turned by the light ray due to reflection. 180° - i - r

Question 5

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Answer 5

The angle of reflection r is always equal to the angle of incidence i
The incident ray, the reflected ray and normal all lie on the same plane, which means that all three lines can be drawn on a flat sheet of paper.

Question 6

What surfaces obey the law of reflection?

Answer 6

All surfaces.

Question 7

Explain the reflection formed by a smooth surface. Name an example of such a surface.

Answer 7

When the surface of an object is smooth and flat, normals at different points on the surface are parallel to each other. When a parallel beam of light falls on it, the reflected beam is also parallel. Hence a regular reflection is formed, producing a clear, sharp image.
A calm water surface.

Question 8

Explain the reflection that is formed by most surfaces.

Answer 8

Most surfaces are not perfectly smooth. Normals at different points are irregular in direction. Following the laws of reflection, parallel light is sent off irregularly in many different directions. Hence, a diffuse reflection is formed, producing a distorted, blurred image.
A ruffled water surface.