Uses of the concave mirror and the convex mirror in our daily life
Uses of concave mirror
The concave mirror is a converging mirror , so that it is used for many purposes , It is used as a torch to reflect the light , It is used in the aircraft landing at the airports to guide the aeroplanes , It is used in shaving to get an enlarged and erect image of the face .
The concave mirror is used in front lights of cars to reflect the light , It is used in marine lighthouses that are found at the marine ports and at the airports to guide the ships and it is used in the solar ovens .
The concave mirror is used in the solar ovens and the solar furnaces to collect a large amount of solar energy in the focus of the mirror for cooking food , heating water , recharging power backups or melting metals respectively .
Concave mirrors are used in satellite dishes , They are used in telescopes , Dentist and ENT doctors use them to obtain a larger image than the original of the teeth , ear or skin etc .
Concave mirrors are used in the electron microscopes and magnifying glasses , They are used in the visual bomb detectors and they are used in the flash light mirror of camera .
Real image and Virtual image
The real image is formed as a result of the intersection of the reflected light rays , It can be received on a screen , And it is always inverted .
The virtual image is formed as a result of the intersection of the reflected light rays extensions , It can not be received on a screen , It is always erect ( upright ) .
The focus of concave mirror
The focus of the concave mirror is produced due to the collection of the reflected rays emitted from a far object such as the sun , The rays after being reflected collect in one lit point which is called the focus of the mirror that can be received on the screen .
The distance between the focus of the mirror and the pole of the mirror = ½ the radius of mirror curvature and it is called the focal length of the mirror .
When the incident light ray parallel to the principal axis , It reflects passing through the focus , When the incident light ray that passes through the focus , It reflects parallel to the principal axis , When the incident light ray that passes through the center of curvature , It reflects back on itself .
Cases of formation of the images by the concave mirror
When the position of the object is very far , the position of the image is at the focus , The image is real and very tiny ( dot ) .
The object is at a distance greater than the radius of curvature ( after the center of curvature ) , The image is at a distance greater than the focal length but less than the double of focal length ( between the focus and the curvature ) , The image is real , inverted and diminished ( small ) .
When the object is at the center of curvature ( at a distance equals the radius of curvature ) , The image will be at the curvature center , The image will real , inverted and equal to the object .
When the object is between the center of curvature and the focus ( at a distance more than the focal length but less than the radius of curvature ) , The image is after the center of curvature ( at a distance greater than the radius of curvature ) , The image is real , inverted and enlarged ( magnified ) .
When the object is between the focus and the pole ( at a distance less than the focal length , The image is behind the mirror , The image is virtual , upright ( erect ) and magnified .
When the object is at the focus , No image is formed , The image is at infinity where the rays penetrate as parallel .
Uses of convex mirror
The convex mirror is used as side-view mirror on the passenger’s side of a car because it forms an erect and smaller image for the way behind the car .
The convex mirror is suitable for convenient shop and big supermarket and any other corner where need anti-thief , It is used in the turning off the road and parking .
Convex mirrors are used inside the buildings , They are also used in making lenses of sunglasses , They are used in magnifying glass , They are used in securities and they are used in telescopes .
They can be used as street light reflectors because they can spread the light over a bigger area , They are put on the corners of roads so that you can see any cars coming to avoid the collisions and they are used as ceiling dome mirrors .
Properties of the formed image by the convex mirror
Wherever the position of the object in front of the convex mirror , the image is smaller than the object , It is upright ( erect ) , It is virtual ( not received on a screen ) .