The Focal Length Of A Convex Mirror
University of Kerbala college of dentistry
First Stage Group "D"
Name: Ahmed Mohammed Ali
Name of exp: The focal length of convex mirror
Date of exp: 16/1/2015
Sub group: Ali Emad - mobeen jafer - mortadha abd al-aaly
Apparatus
Convex mirror and holder, small plane mirror and wooden clamp Convex lens and holder. two mounted pins, metre rule or optical bench.
Method:
Place a mounted pin at a distance from the convex lens greater than the focal length so that a real image of the pin is produced. Locate this image by means of the second pin. Place the convex mirror between this second pin and the lens and adjust its position until the light reflected from the mirror passes back through the lens and forms an image coincident with the object pin. This occurs when the rays of light leaving the lens strike the mir normally and are reflected back along their original paths. Note. It is often a good plan to invert this procedure and do the reflection part of the experiment first. There is then no danger of wasting time on an object position which produces an image whose distance from the lens is less than the radius of curvature of the mirror.
Theory:
O is the object pin and I the realimage formed when the mirror is not present.When te mirror is interposed so that the rays strike it normally and are reflected back through the lens to form an image coincident with O, the centre of curvature of the mirror coincides with I.
Hence PI= radius of curvature r of the and f= 1/2r.
Disscussion:
A ray of light passing through a glass lens maybe refracted twice- first where it enters the glass and, then where it leaves the glass. There is a net deviation of the ray from its original direction. Usually each surface of the lens is part of a sphere.
Lenses with two spherical surfaces sufficiently close together that the distance between them ( the thickness of a lens) can be neglected are called thin lenses . If their thickness cannot be neglected,
First Stage Group "D"
Name: Ahmed Mohammed Ali
Name of exp: The focal length of convex mirror
Date of exp: 16/1/2015
Sub group: Ali Emad - mobeen jafer - mortadha abd al-aaly
Apparatus
Convex mirror and holder, small plane mirror and wooden clamp Convex lens and holder. two mounted pins, metre rule or optical bench.
Method:
Place a mounted pin at a distance from the convex lens greater than the focal length so that a real image of the pin is produced. Locate this image by means of the second pin. Place the convex mirror between this second pin and the lens and adjust its position until the light reflected from the mirror passes back through the lens and forms an image coincident with the object pin. This occurs when the rays of light leaving the lens strike the mir normally and are reflected back along their original paths. Note. It is often a good plan to invert this procedure and do the reflection part of the experiment first. There is then no danger of wasting time on an object position which produces an image whose distance from the lens is less than the radius of curvature of the mirror.
Theory:
O is the object pin and I the realimage formed when the mirror is not present.When te mirror is interposed so that the rays strike it normally and are reflected back through the lens to form an image coincident with O, the centre of curvature of the mirror coincides with I.
Hence PI= radius of curvature r of the and f= 1/2r.
Disscussion:
A ray of light passing through a glass lens maybe refracted twice- first where it enters the glass and, then where it leaves the glass. There is a net deviation of the ray from its original direction. Usually each surface of the lens is part of a sphere.
Lenses with two spherical surfaces sufficiently close together that the distance between them ( the thickness of a lens) can be neglected are called thin lenses . If their thickness cannot be neglected,