| Plane Mirrors |
| The use of plane mirrors dates back to many decades ago.Today,every home has one or two plane mirrors in their toilets or bathrooms.Women,the world over,cannot do without looking mirrors. They use them to see their beauty and in most cases,you find them in their handbags. Plane mirror can be described as a plane sheet of glass covered with silver on one of its faces. |
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When an object is placed before a plane mirror,the image of the object can be seen in the mirror.The image produced by a plane mirror has the following characteristics,viz,
- Virtual.
- Upright.
- As far behind the mirror as the object in front of it.
- It is laterally inverted.
- Same size as the object.
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| A plane mirror has a magnification.Magnification is defined as the ratio of the image height to the object height.The magnification of image produced by a plane mirror is 1. |
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| If an object is held between two mirrors placed at an angle,the number of images produced by the mirrors vary with the angles with which the mirrors are held.For instance,3 images are formed when an object is held between two mirrors placed at an angle of 900.A mathematical expression can be used to determine the number of images so formed. The mathematical expression can be written as follows: |
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| n=3600/x0-1 |
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Where:
n = Number of images
x0 = Angle between the mirrors. |
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| An object held between parallel mirrors would produce infinite images. The relationships between the angles and number of images can be tabulated below. |
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| Angles | Number of images | | 100 | 35 | | 20 0 | 17 | | 30 0 | 11 | | 40 0 | 8 | | 60 0 | 5 | | 90 0 | 3 | | 120 0 | 2 | | 180 0 | 1 | | 360 0 | 0 | | Parallel | Infinite number of images |
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