How to Draw a Ray Diagram for a Plane Mirror?

Drawing a ray diagram for a plane mirror helps visualize how images are formed. Here's a step-by-step guide:

Steps to Draw a Ray Diagram for a Plane Mirror

1. Draw the Mirror and Object:

   • Start by drawing a vertical line to represent the plane mirror. Indicate the reflecting surface by adding small diagonal lines on the back (non-reflecting) side of the mirror.
   • Draw the object in front of the mirror. This can be a simple arrow or a stick figure.

2. Draw Incident Rays:

   • From the top of your object, draw at least two incident rays towards the mirror.
     • Ray 1: Draw a ray that travels from the object perpendicular (straight) to the mirror.
     • Ray 2: Draw another ray from the top of the object that strikes the mirror at an angle.

3. Draw Reflected Rays:

   • Ray 1: The reflected ray of the perpendicular incident ray will bounce straight back, following the same path it came from.

   • Ray 2: The reflected ray will have the same angle relative to the normal (a line perpendicular to the mirror surface at the point of incidence) as the incident ray but on the opposite side of the normal. This is called the law of reflection, where the angle of incidence equals the angle of reflection. As noted in the provided YouTube reference, we are working inside the mirror as it is a reflection.

     • Use a protractor to measure the angle between your Ray 2 and the mirror surface. Draw the reflected ray with this same angle on the other side of the normal.

4. Draw Virtual Rays:

• Extend the reflected rays backwards behind the mirror as dashed lines. These are called virtual rays.

5. Locate the Image:
   • The point where the virtual rays intersect is where the image of the top of your object is formed.
   • Repeat step 2-4 for the bottom of your object.
   • Draw the full image of your object using the image points, behind the mirror.

Understanding the Image Formed

• The image formed by a plane mirror is virtual. This means it is formed by the apparent intersection of reflected rays and cannot be projected onto a screen.
• The image is erect (upright) and is the same size as the object.
• The image is laterally inverted, which means left and right appear to be flipped.
• The image is located at the same distance behind the mirror as the object is in front of it.

Example:

Step	Description
1	Draw mirror as a vertical line with reflective and non-reflective sides
2	Draw the object in front of the mirror.
3	Draw two incident rays from the top of the object.
4	Draw the two reflected rays by applying the law of reflection.
5	Extend the reflected rays behind the mirror as dashed (virtual) lines.
6	Mark the point where the extended rays meet as the image point.
7	Repeat steps 3-6 for the bottom of the object to determine image bottom.
8	Draw the complete virtual image by connecting the image points.

Following these steps will help you understand how plane mirrors create reflections.